Name: measuring magnetically-tuned ferroelectric polarization in liquid crystals
Uploaded: 2018-08-15T14:45:00.000+00:00
Duration: 7 min 3 s
Description: Watch this Scientific Journal Video about Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals at JoVE.com

私たちの実験では彼の助けを教授高西を感謝いたします。また、DIC 株式会社に感謝、ここで学んだ化合物を提供するため。この作品は、日本学術振興会研究員 (16J02711)、日本学術振興会科研費助成番号の費補助金によって支えられた 17 H 01143 と大学院「インタラクティブな材料士官候補生プログラム」をリードするためのプログラム。

1. 液晶セルおよび細胞のギャップの決定の準備
<ol><li>
液晶セルの作製
	<ol>
<li>カット希望のサイズに 1 つの側面にインジウム/スズ酸化物 (ITO) コートガラス基板 (典型的なサイズ: 10 x 10 x 1.1 mm、図 2 a)。基板をカットするには、ガラス カッターで自分の顔に線をスクラッチし、手動で余分なガラスを断ちます。</li>
		<li>30 分 35 khz 超音波風呂の洗剤を使用してカット ガラス基板 10 分脱イオン置換用超音波洗浄槽で脱イオン水で洗浄し洗浄水し、基板を 5 回洗浄 (図 2 b) 汚染物質を除去します。基板の広い面に触れないように注意して、-ダスター-エアガンと残りの水を吹き飛ばします。</li>
		<li>30 の 5000 rpm でソリューション洗浄基板とスピン コートの ito 面にポリイミド ソリューション (テーブルの材料の配置レイヤー平面) を点滴 s (図 2)。200 ° C、溶媒を除去し、ポリイミド薄膜を治す 1 h で基板を焼きます。</li>
		<li>XZステージ上基板を置き、基板の伊藤とポリイミド コーティング面を上向きにセットします。ベルベットの布と修正による基板上への空気 (図 2 D) を吸引で覆われたローラーの下で基板を配置します。ステージの高さを調整することによって、ローラーで基板上に均一で柔らかい圧力を適用します。 注: ここでは、XZ ステージは、大阪大学で機械工場によって作られました。</li>
		<li>ローラを回転させ、前後 5 回ベルベットの布で基板を摩擦する水平方向に沿ってローラーの下で舞台を移動します。ラビング処理配向膜の基板に付着した汚れ、1 分間 10-50 mL のガラス容器にイソプロピル アルコールに手をつけるし、80 ° C で、数分間乾かします。</li>
		<li>スペーサーとして 12 μ m 厚フラット樹脂フィルムと 2 枚の基板を接着します。接着ポイントが基板の端にのみ配置されて伊藤とポリイミド接着基板の内側が塗られることに注意してください。反対側の基板 antiparallel をこすり、基板 (図 2 e) の両方の電気端子に十分なスペースを提供する (約 2 mm) をシフトされてわずかことを確認します。</li>
		<li>端末を使用して銀導電ペースト (図 2 f) 上記スペースの導電性ワイヤを接着します。銀導電性ペーストで溶媒を削除する 1 h 150 ° C で導電性ワイヤと基板を焼きます。</li>
	</ol>
</li>
	<li>
セルギャップの定量19<ol>
<li>1.1.7 で広い顔に垂直伝播する白色光を使用した空白セルを照射します。光分光装置による、伝送スペクトルを測定し、擬似正弦波発振は、ファブリ ・ ペロー効果20が表示される (図 3) を確認します。</li>
		<li>Dの関係を使用して、ギャップdを推定、 λ1λ22 (λ2-λ1) を = 波長λ1とλ2透過スペクトルの隣接するピーク波長のペアを表します。</li>
	</ol>
</li>
</ol>2. 液晶混合物の細胞への導入準備
<ol><li>5-octyl-2-(4-octyloxyphenyl) ピリミジン化合物 2 つをミックス (化合物1:図 4 a) と (S)-5-decyl-2-[4(2-fluorodecyloxy) フェニル] ピリミジン (複合2:図 4 b) ガラス瓶の 3:1 の質量比で。合計 (化合物1の化合物2の 25 mg 75 mg) でソリューションの 100 mg を準備します。</li>
	<li>2.1 からの混合物が等方性液体段階 (図 5) では温度 80 ° C の温度を維持する、熱いステージにステップ 1.1.7 から準備された空白のセルを置きます。ヘラと毛細管を使用してセルにステップ 2.1 からの混合物を紹介します。セル温度 80 ° C、30 分を維持し、約 5 ° C/分の速度で室温まで冷却します。</li>
</ol>3. サンプル評価
<ol><li>セルの場所は、光照射 2 つ交差偏光板との間の熱いステージ上ステップ 2.2 からの混合物でいっぱい。顕微鏡による室温から 5 ° C/分の速度で 80 ° C の温度の変化との混合物のテクスチャを観察 (とチューニング 〜 600 の範囲でショートパス フィルターに応じて、視認性を高めるために nm) から液晶フェーズを洗い出して、偏光顕微鏡写真21 (図 6)。</li>
	<li>(図 5) の観測のテクスチャから相転移シーケンスと遷移温度を決定します。SmC * フェーズでは、ダブル ストライプの幅として螺旋ピッチを推定します。</li>
	<li>示差熱分析で 2.1 で作製した混合物の一次相転移温度を確認 (DTA;テーブルの材料と製造元の指示を参照してください)、一次の段階でピーク (または dip) 異常を提供します。遷移 (図 7)。</li>
</ol>4. 誘電体と電気磁気測定
<ol><li>商業の超伝導磁石を準備温度コント ローラー (2 400 K) と磁場 (9 T) まで装備 (材料の表を参照してください)。</li>
	<li>3 つの主要部分から成っている超電導磁石用自家製挿入の準備: サンプル スペース、4 つの同軸ケーブルとコネクタ端子 (図 8 a) を含むロッド。</li>
	<li>2.2 挿入 (図 8 b) のサンプル スペースで準備セルを接着します。標本空間の (高低) の端子にはんだ付けによるセルの 2 つの導電性ワイヤを接続します。セルの基板に平行な方向に磁場を適用するように細胞の向きのことを確認します。サンプル温度を正確に測定、超電導磁石に挿入を導入するためにセルの広い平面上には、温度計を配置します。</li>
	<li>LCRメータにコネクタ端子を接続 (材料の表を参照してください) 同軸ケーブルを使用。(製造元を参照してくださいと私たちの以前の仕事16) LCRメーターで温度・磁場の関数として準四端子法による誘電定数の測定します。</li>
	<li>電位計にコネクタ端子を接続 (材料の表を参照してください) 同軸ケーブルを使用。抜本的な磁場と温度一定速度 (1.0 T/分抜本的な磁場と温度を全面的な 5 K/分; 参照中、電位計と変位電流の磁場・温度依存性を測定します。製造元の指示と私たちの以前の仕事16)。変位は、時間の関数として電流を統合することにより電気分極を取得します。</li>
</ol>

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著者が明らかに何もありません。

実験の結果, 液晶結合私を示される正常にここで説明したメソッド。観測された私と磁気誘電効果することができます固定スメクティック層構造における分子配向の配向遷移に関連付けられました。ただし、レイヤー構造の層法線方向n0は磁気異方性磁気フィールドを適用することによっても変更できます。これは分子がnとその磁気異方性によ?...

(私) 効果、磁気 (電界) による電気分極 (磁化) の誘導、電気磁気に関する研究、センサーおよびストレージ ・ テクノロジーなどのアプリケーションの新しい種類の方が注目されています。最近の研究私のマルチフェロイックス1,2,3,4, ターゲット システム固体、無機、有機などの様々 なタイプに私の分野で研究を拡張し、金属有機性フレームワーク、スピン-格子カップリングを利用して器用5,6,7,の8,9。ただし、室温動作私の実用的な利用のために達成する必要があります自分の ME と材料・ カップリング、挑戦的な問題だし、単相材料の非常に限られた数は、部屋温度として報告されています。10日に magnetoelectrics。
私に関しても検討されて、時に部分的な位置の 1 つの配向秩序を有する液晶材料13,1412,近年11、、、15. 1 つ私として液晶の利点の材料は、動作温度 - 液晶相は通常室温付近安定。例私の液晶はこれまで報告が垂直磁気異方性磁気ナノ血小板と最も簡単な液晶相として知られているネマティック相を示す液晶複合所持 1 次元のみ配向秩序15。それは私に影響を与える、コンバース血小板結合と分子配向の電場を介したの電界印加による磁化の誘導を示しています。
さらに最近、私を確立する別のユニークな戦略液晶の効果提案16歳でした。この戦略の焦点は、スメクチック層と呼ばれる拡散層構造の一次元の位置の順序でキラルなスメクティック C (SmC *) フェーズを作成します。SmC の段階の 1 つの特徴は、分子配向ベクトルnはローカル電気双極子モーメントpとつながれることです。この相関関係は、傾斜配向スメクティック層法線をn0と、キラリティー誘起ミラー (と反転) 対称性の破れの分子に関して、棒状分子の組み合わせによって提供されます。対称性の観点から、旧D∞h (いわゆる SmA 相、図 1 a) から対称に変更C2h (いわゆる SmC フェーズ、図 1 b) と対称性はC2に減少したので、後者は、 C2hのミラー対称性を破る (SmC * フェーズでは、図 1の各レイヤーを参照してください)。SmC * 各層のn0とnの両方に通常はCの2軸に沿って有限偏波の存在となっています。Nとpの間の強い結合は液晶の強誘電性に不可欠です。SmC * 段階でn層 (図 1)、螺旋的で整合し、従って巨視的分極がないです。このような液晶の強誘電性はn表面安定化強誘電性液晶 (SSFLC) 状態 (図 1) として知られている均一配向状態を安定させる強いの表面効果を使用して実現されます。常に強誘電体の分極反転がnとp17間の結合を通じて双安定配向状態の切り替えに伴うことに注意してください。逆の効果として、SmC の段階の分子の向きの変化は電気分極の変化を生じさせると予想されます。磁気異方性磁気要素および/または液晶分子と固体の結晶状態より弱い分子相互作用による液晶状態のnの柔軟性で芳香環の回転によって引き起こされるnです。また磁場印加による可変。したがって、SmC のフェーズは、強誘電性液晶状態と同様、磁気誘導の均一配向状態に変換できます。したがって、電気分極の開発、 n pですべてのレイヤー結合の配向に起因する、直接私に影響を与える、磁場印加による電気分極の誘導を実現します。
カップリングと ME を検出するための方法論は、私の調査のため液晶セルを準備する手順を紹介する効果。メソッドで報告された液晶セルの準備のための以前18 を詳細します。ここでは、誘電体と私のためのこの方法の測定を変更しました。ここで詳しく説明の方法で室温で SmC のフェーズを示す液晶磁気調整電気分極は、直接私に影響を与えるを検出した.

<table><tbody><tr><td>&lt;strong&gt;Material&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Compound 1: Figure 4(A)</td><td>DIC Co., Ltd.</td><td>&amp;ndash;N/A</td><td>PYP-8O8</td></tr><tr><td>Compound 2: Figure 4(B)</td><td>DIC Co., Ltd.</td><td>N/A</td><td>PYP-10O10F</td></tr><tr><td>ITO-coated glass substrates</td><td>Sigma-Aldrich Inc.</td><td>703192-10PK</td><td></td></tr><tr><td>Detergent</td><td>Wako Pure Chemical Industries, Ltd.</td><td>031-10401</td><td></td></tr><tr><td>Alignment layer planer</td><td>JSR Co., Ltd.</td><td>AL1254</td><td></td></tr><tr><td>Spacer</td><td>Teijin Film Solutions Co., Ltd.</td><td>Q51-12</td><td></td></tr><tr><td>Glue</td><td>Huntsman Inc.</td><td>ARALDITE RT30</td><td>For gluing two substrates</td></tr><tr><td>Glue</td><td>M&amp;amp;I Materials ltd.</td><td>Apiezon H Grease</td><td>For gluing a cell and homemade insert</td></tr><tr><td>Silver paste</td><td>Fujikura Kasei Co., Ltd.</td><td>D-753</td><td></td></tr><tr><td>&lt;strong&gt;Equipment&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Ultrasonic cleaner</td><td>AS ONE Corp.</td><td>AS52GTU</td><td></td></tr><tr><td>Spin coater</td><td>Mikasa Co. Ltd.</td><td>1H-D7</td><td></td></tr><tr><td>Polarized optical microscope</td><td>Nikon Co., Ltd.</td><td>ECLIPSE LV100N POL</td><td></td></tr><tr><td>Short-pass filter</td><td>Thorlabs Inc.</td><td>FB600-40</td><td></td></tr><tr><td>Optical spectrometer</td><td>Ocean Optics Inc.</td><td>USB2000+UV-VIS</td><td></td></tr><tr><td>Differential thermal analyzer</td><td>Rigaku Co., Ltd.</td><td>Thermo plus EVO2</td><td></td></tr><tr><td>Superconducting magnet</td><td>Quantum Design Inc.</td><td>PPMS</td><td></td></tr><tr><td>LCR meter</td><td>Keysight Technologies Ltd.</td><td>E4980A</td><td></td></tr><tr><td>Electrometer</td><td>Keithley Instruments Inc.</td><td>6517A</td><td></td></tr></tbody></table>

measuring magnetically-tuned ferroelectric polarization in liquid crystals

材料 (鉄) 電気と磁気間のカップリング現象を示す、すなわち、マグネトエレク トリック効果、大量のセンサーやストレージなど将来のデバイス技術の潜在的な応用のための関心を集めています。ただし、通常利用する材料の磁性金属イオン (またはラジカル) を含むが、従来のアプローチは主要な問題を抱えている: 室温でカップリング現象を表示する唯一のいくつかの素材が発見されています。最近では、室内温度 magnetoelectrics を達成するために新しいアプローチを提案する.従来のアプローチとは対照的代替提案は完全に異なる素材、「液晶」、磁性金属イオンから自由焦点を当て。このような液晶の磁場を構成する分子と分子の磁気異方性を対応する電気分極の配向状態を制御する利用できます。マグネトエレク トリック効果の前例のない機構です。このコンテキストでは、このペーパーは、磁場、液晶で、つまり、直接マグネトエレク トリック効果誘起強誘電特性を測定するためのプロトコルを提供します。ここで詳しく説明の方法で正常に室温で液晶のキラル スメクティック C 相の電気分極の磁場調整を検出しました。直接電気磁気応答に影響を与える、構成分子の柔軟性と共に撮影方法を紹介液晶セル室温 magnetoelectrics としてより多くの機能を取得するようになるし、関連付けられています。光学材料

プロトコルは、場合私は液晶のサンプルの効果の観察だけ成功とみなされます。ここで直接私の前述の手順で作製した液晶サンプルで効果を測定しました。測定のための面内磁場は最大の磁場誘起分極がこの構成16で検出されたため (スメクティック層に垂直) のラビング方向から約 45 ° によって傾斜角度を適用しました。
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Watch this Scientific Journal Video about Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals at JoVE.com

Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals

本報告では液晶の磁場の適用による直接マグネトエレク トリック効果、すなわち分極の誘導を検討するプロトコルを提案します。このプロトコルは、部屋温度 magnetoelectrics を達成するために、液晶の柔らかさでサポートされている、ユニークなアプローチを提供します。

液晶における強誘電分極の磁場調整を測定

Materials showing coupling phenomena between magnetism and (ferro)electricity, i.e., magnetoelectric effects, have attracted a great deal of attention due ...

measuring-magnetically-tuned-ferroelectric-polarization-liquid

Universidad de Cartagena UDEC

Research

JoVE Journal

Engineering

8.7K ビュー.  Osaka University. 本報告では液晶の磁場の適用による直接マグネトエレク トリック効果、すなわち分極の誘導を検討するプロトコルを提案します。このプロトコルは、部屋温度 magnetoelectrics を達成するために、液晶の柔らかさでサポートされている、ユニークなアプローチを提供します。

ビデオ: Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals

Chemical Vapor Deposition of an Organic Magnet, Vanadium Tetracyanoethylene

Recent progress in the field of organic materials has yielded devices such as organic light emitting diodes (OLEDs) which have advantages not found in traditional materials, including low cost and mechanical flexibility. In a similar vein, it would be advantageous to expand the use of organics into high frequency electronics and spin-based electronics. This work presents a synthetic process for the growth of thin films of the room temperature organic ferrimagnet, vanadium tetracyanoethylene (V[TCNE]x, x~2) by low temperature chemical vapor deposition (CVD). The thin film is grown at &#60;60 &#176;C, and can accommodate a wide variety of substrates including, but not limited to, silicon, glass, Teflon and flexible substrates. The conformal deposition is conducive to pre-patterned and three-dimensional structures as well. Additionally this technique can yield films with thicknesses ranging from 30 nm to several microns. Recent progress in optimization of film growth creates a film whose qualities, such as higher Curie temperature (600 K), improved magnetic homogeneity, and narrow ferromagnetic resonance line-width (1.5 G) show promise for a variety of applications in spintronics and microwave electronics.

We present the synthesis of the organic-based ferrimagnet vanadium tetracyanoethylene (V[TCNE]x, x~2) via low temperature chemical vapor deposition (CVD). This optimized recipe yields an increase in Curie temperature from 400 K to over 600 K and a dramatic improvement in magnetic resonance properties.

有機マグネットの化学気相堆積、バナジウムテトラ

Recent progress in the field of organic materials has yielded devices such as organic light emitting diodes (OLEDs) which have advantages not found in ...

化学

Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers

Magnetic beads with ~1.9 &#181;m average diameter were used to transport microliter volumes of liquids between contiguous liquid segments with a tube for the purpose of investigating phase change of those liquid segments. The magnetic beads were externally controlled using a magnet, allowing for the beads to bridge the air valve between the adjacent liquid segments. A hydrophobic coating was applied to the inner surface of the tube to enhance the separation between two liquid segments. The applied magnetic field formed an aggregate cluster of magnetic beads, capturing a certain liquid amount within the cluster that is referred to as carry-over volume. A fluorescent dye was added to one liquid segment, followed by a series of liquid transfers, which then changed the fluorescence intensity in the neighboring liquid segment. Based on the numerical analysis of the measured fluorescence intensity change, the carry-over volume per mass of magnetic beads has been found to be ~2 to 3 &#181;l/mg. This small amount of liquid allowed for the use of comparatively small liquid segments of a couple hundred microliters, enhancing the feasibility of the device for a lab-in-tube approach. This technique of applying small compositional variation in a liquid volume was applied to analyzing the binary phase diagram between water and the surfactant C12E5 (pentaethylene glycol monododecyl ether), leading to quicker analysis with smaller sample volumes than conventional methods.

Here, we present a protocol to investigate multi-component phase diagrams using externally controlled magnetic beads as liquid carriers in a lab-in-tube approach. This approach can aid in applications that seek to gather further information on phase change in complex liquid systems.

相図の特徴付け液体担体として磁気ビーズを使用しました

Magnetic beads with ~1.9 &#181;m average diameter were used to transport microliter volumes of liquids between contiguous liquid segments with a tube for ...

工学

Automation of Mode Locking in a Nonlinear Polarization Rotation Fiber Laser through Output Polarization Measurements

When a laser is mode-locked, it emits a train of ultra-short pulses at a repetition rate determined by the laser cavity length. This article outlines a new and inexpensive procedure to force mode locking in a pre-adjusted nonlinear polarization rotation fiber laser. This procedure is based on the detection of a sudden change in the output polarization state when mode locking occurs. This change is used to command the alignment of the intra-cavity polarization controller in order to find mode-locking conditions. More specifically, the value of the first Stokes parameter varies when the angle of the polarization controller is swept and, moreover, it undergoes an abrupt variation when the laser enters the mode-locked state. Monitoring this abrupt variation provides a practical easy-to-detect signal that can be used to command the alignment of the polarization controller and drive the laser towards mode locking. This monitoring is achieved by feeding a small portion of the signal to a polarization analyzer measuring the first Stokes parameter. A sudden change in the read out of this parameter from the analyzer will occur when the laser enters the mode-locked state. At this moment, the required angle of the polarization controller is kept fixed. The alignment is completed. This procedure provides an alternate way to existing automating procedures that use equipment such as an optical spectrum analyzer, an RF spectrum analyzer, a photodiode connected to an electronic pulse-counter or a nonlinear detecting scheme based on two-photon absorption or second harmonic generation. It is suitable for lasers mode locked by nonlinear polarization rotation. It is relatively easy to implement, it requires inexpensive means, especially at a wavelength of 1550 nm, and it lowers the production and operation costs incurred in comparison to the above-mentioned techniques.

A protocol to detect and automate mode locking in a pre-adjusted nonlinear polarization rotation fiber laser is presented. The detection of a sudden change in the output polarization state when mode locking occurs is used to command the alignment of an intra-cavity polarization controller in order to find mode-locking conditions.

出力偏光測定を通じて非線形偏波回転ファイバレーザにおけるモードロックの自動化

When a laser is mode-locked, it emits a train of ultra-short pulses at a repetition rate determined by the laser cavity length. This article outlines a ...

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets

In liquid crystal (LC) physical chemistry, molecules near the surface play a great role in controlling bulk orientation. Thus far, mainly to achieve desired molecular orientation states in LC displays, the "static" surface property of LCs, so-called surface anchoring, has been intensively studied. As a rule of thumb, once the initial orientation of LCs is "locked" by specific surface treatments, such as rubbing or treatment with a specific alignment layer, it hardly changes with temperature. Here, we present a system exhibiting an orientational transition upon temperature variation, which conflicts with the consensus. Right on the transition, the bulk LC molecules experience the orientational rotation, with 90&#176; between the planar (P) orientation at high temperatures and the vertical (V) orientation at low temperatures in the first-order transitional manner. We have tracked thermodynamic surface anchoring behavior by means of polarizing optical microscopy (POM), dielectric spectroscopy (DS), high-resolution differential scanning calorimetry (HR-DSC), and grazing incidence X-ray diffraction (GI-XRD) and reached a plausible physical explanation: that the transition is triggered by a growth of surface wetting sheets, which impose the V orientation locally against the P orientation in the bulk. This landscape would provide a general link explaining how the equilibrium bulk orientation is affected by surface-localized orientation in many LC systems. In our characterization, POM and DS are advantageous by offering information on the spatial distribution of the orientation of LC molecules. HR-DSC gives information about the precise thermodynamic information on transitions, which cannot be addressed by conventional DSC instruments due to limited resolution. GI-XRD provides information on surface-specific molecular orientation and short-range orderings. The goal of this paper is to present a protocol for preparing a sample that exhibits the transition and to demonstrate how the thermodynamic structural variation, both in the bulk and on surfaces, can be analyzed through the abovementioned methods.

Here, we present a protocol to trigger an orientational transition of a liquid crystal in response to temperature. Methodologies are described for preparing a sample in order to observe the transition and the detailed transitional evolution.

界面湿潤シートの熱力学的成長によって引き起こされる液晶の配向転移

In liquid crystal (LC) physical chemistry, molecules near the surface play a great role in controlling bulk orientation. Thus far, mainly to achieve ...

Fabrication Procedures and Birefringence Measurements for Designing Magnetically Responsive Lanthanide Ion Chelating Phospholipid Assemblies

Bicelles are tunable disk-like polymolecular assemblies formed from a large variety of lipid mixtures. Applications range from membrane protein structural studies by nuclear magnetic resonance (NMR) to nanotechnological developments including the formation of optically active and magnetically switchable gels. Such technologies require high control of the assembly size, magnetic response and thermal resistance. Mixtures of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and its lanthanide ion (Ln3+) chelating phospholipid conjugate, 1,2-dimyristoyl-sn-glycero-3-phospho-ethanolamine-diethylene triaminepentaacetate (DMPE-DTPA), assemble into highly magnetically responsive assemblies such as DMPC/DMPE-DTPA/Ln3+ (molar ratio 4:1:1) bicelles. Introduction of cholesterol (Chol-OH) and steroid derivatives in the bilayer results in another set of assemblies offering unique physico-chemical properties. For a given lipid composition, the magnetic alignability is proportional to the bicelle size. The complexation of Ln3+ results in unprecedented magnetic responses in terms of both magnitude and alignment direction. The thermo-reversible collapse of the disk-like structures into vesicles upon heating allows tailoring of the assemblies&#39; dimensions by extrusion through membrane filters with defined pore sizes. The magnetically alignable bicelles are regenerated by cooling to 5 &#176;C, resulting in assembly dimensions defined by the vesicle precursors. Herein, this fabrication procedure is explained and the magnetic alignability of the assemblies is quantified by birefringence measurements under a 5.5 T magnetic field. The birefringence signal, originating from the phospholipid bilayer, further enables monitoring of polymolecular changes occurring in the bilayer. This simple technique is complementary to NMR experiments that are commonly employed to characterize bicelles.

Fabrication procedures for highly magnetically responsive lanthanide ion chelating polymolecular assemblies are presented. The magnetic response is dictated by the assembly size, which is tailored by extrusion through nanopore membranes. The assemblies&#39; magnetic alignability and temperature-induced structural changes are monitored by birefringence measurements, a complimentary technique to nuclear magnetic resonance and small angle neutron scattering.

製作手順と磁気応答性ランタノイド イオンのキレート リン脂質アセンブリを設計するための複屈折測定

Bicelles are tunable disk-like polymolecular assemblies formed from a large variety of lipid mixtures. Applications range from membrane protein structural ...

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

We discuss in this article the experimental measurements of the molecules in liquid crystal (LC) phase using the time-resolved infrared (IR) vibrational spectroscopy and time-resolved electron diffraction. Liquid crystal phase is an important state of matter that exists between the solid and liquid phases and it is common in natural systems as well as in organic electronics. Liquid crystals are orientationally ordered but loosely packed, and therefore, the internal conformations and alignments of the molecular components of LCs can be modified by external stimuli. Although advanced time-resolved diffraction techniques have revealed picosecond-scale molecular dynamics of single crystals and polycrystals, direct observations of packing structures and ultrafast dynamics of soft materials have been hampered by blurry diffraction patterns. Here, we report time-resolved IR vibrational spectroscopy and electron diffractometry to acquire ultrafast snapshots of a columnar LC material bearing a photoactive core moiety. Differential-detection analyses of the combination of time-resolved IR vibrational spectroscopy and electron diffraction are powerful tools for characterizing structures and photoinduced dynamics of soft materials.

Here, we present the protocols of differential-detection analyses of time-resolved infrared vibrational spectroscopy and electron diffraction which enable observations of the deformations of local structures around photoexcited molecules in a columnar liquid crystal, giving an atomic perspective on the relationship between the structure and the dynamics of this photoactive material.

光応答性液晶の構造ダイナミクスを観察する手法

We discuss in this article the experimental measurements of the molecules in liquid crystal (LC) phase using the time-resolved infrared (IR) vibrational ...

A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy

Flexible non-volatile memories have received much attention as they are applicable for portable smart electronic device in the future, relying on high-density data storage and low-power consumption capabilities. However, the high-quality oxide based nonvolatile memory on flexible substrates is often constrained by the material characteristics and the inevitable high-temperature fabrication process. In this paper, a protocol is proposed to directly grow an epitaxial yet flexible lead zirconium titanate memory element on muscovite mica. The versatile deposition technique and measurement method enable the fabrication of flexible yet single-crystalline non-volatile memory elements necessary for the next generation of smart devices.

In this paper, we present a protocol to directly grow an epitaxial yet flexible lead zirconium titanate memory element on muscovite mica.

作製と Van Der waals 力ヘテロエピタキシーに基づくフレキシブル強誘電性要素の測定法

Flexible non-volatile memories have received much attention as they are applicable for portable smart electronic device in the future, relying on ...

An Electrochemical Cholesteric Liquid Crystalline Device for Quick and Low-Voltage Color Modulation

We demonstrate a method for fabricating a prototype reflective display device that contains cholesteric liquid crystal (LC) as an active component. The cholesteric LC is composed of a nematic LC 4&#39;-pentyloxy-4-cyanobiphenyl (5OCB), redox-responsive chiral dopant (FcD), and a supporting electrolyte 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMIm-OTf). The most important component is FcD. This molecule changes its helical twisting power (HTP) value in response to redox reactions. Therefore, in situ electrochemical redox reactions in the LC mixture allow for the device to change its reflection color in response to electrical stimuli. The LC mixture was introduced, by a capillary action, into a sandwich-type ITO glass cell comprising two glass slides with patterned indium tin oxide (ITO) electrodes, one of which was coated with poly(3,4-ethylenedioxythiophene)-co-poly(ethylene glycol) doped with perchlorate (PEDOT+). Upon application of +1.5 V, the reflection color of the device changed from blue (467 nm) to green (485 nm) in 0.4 s. Subsequent application of 0 V made the device recover the original blue color in 2.7 s. This device is characterized by its fastest electrical response and lowest operating voltage among any previously reported cholesteric LC device. This device could pave the way for the development of next generation reflective displays with low energy consumption rates.

A protocol for the fabrication of a reflective cholesteric liquid crystalline display device containing a redox-responsive chiral dopant allowing quick and low-voltage operation is presented.

迅速かつ低電圧の色変調のため電気化学コレステリック液晶結晶デバイス

We demonstrate a method for fabricating a prototype reflective display device that contains cholesteric liquid crystal (LC) as an active component. The ...

Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures

Photonic crystals are periodic nanostructures that can support a variety of confined electromagnetic modes. Such confined modes are usually accompanied by local enhancement of electric field intensity that strengthens light-matter interactions, enabling applications such as surface-enhanced Raman scattering (SERS) and surface plasmon enhanced sensing. In the presence of magneto-optically active materials, the local field enhancement gives rise to anomalous magneto-optical activity. Typically, the confined modes of a given photonic crystal depend strongly on the wavelength and incidence angle of the incident electromagnetic radiation. Thus, spectral and angular-resolved measurements are needed to fully identify them as well as to establish their relationship with the magneto-optical activity of the crystal. In this article, we describe how to use a Fourier-plane (back focal plane) microscope to characterize magneto-optically active samples. As a model system, here we use a plasmonic grating built out of magneto-optically active Au/Co/Au multilayer. In the experiments, we apply a magnetic field on the grating in situ and measure its reciprocal space response, obtaining the magneto-optical response of the grating over a range of wavelengths and incident angles. This information enables us to build a complete map of the plasmonic band structure of the grating and the angle and wavelength dependent magneto-optical activity. These two images allow us to pinpoint the effect that the plasmon resonances have on the magneto-optical response of the grating. The relatively small magnitude of magneto-optical effects requires a careful treatment of the acquired optical signals. To this end, an image processing protocol for obtaining magneto-optical response from the acquired raw data is laid out.

Photonic band structure enables understanding how confined electromagnetic modes propagate within a photonic crystal. In photonic crystals that incorporate magnetic elements, such confined and resonant optical modes are accompanied by enhanced and modified magneto-optical activity. We describe a measurement procedure to extract the magneto-optical band structure by Fourier space microscopy.

フォトニックナノ構造のスペクトルと角度分解磁気光学特性

Photonic crystals are periodic nanostructures that can support a variety of confined electromagnetic modes. Such confined modes are usually accompanied by ...

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal

Smart viscoelastic materials that respond to specific stimuli are one of the most attractive classes of materials important to future technologies, such as on-demand switchable adhesion technologies, actuators, molecular clutches, and nano-/microscopic mass transporters. Recently it was found that through a special solid-liquid transition, rheological properties can exhibit significant changes, thus providing suitable smart viscoelastic materials. However, designing materials with such a property is complex, and forward and backward switching times are usually long. Therefore, it is important to explore new working mechanisms to realize solid-liquid transitions, shorten the switching time, and enhance the contrast of rheological properties during switching. Here, a light-induced crystal-liquid phase transition is observed, which is characterized by means of polarizing light microscopy (POM), photorheometry, photo-differential scanning calorimetry (photo-DSC), and X-ray diffraction (XRD). The light-induced crystal-liquid phase transition presents key features such as (1) fast switching of crystal-liquid phases for both forward and backward reactions and (2) a high contrast ratio of viscoelasticity. In the characterization, POM is advantageous in offering information on the spatial distribution of LC molecule orientations, determining the type of liquid crystalline phases appearing in the material, and studying the orientation of LCs. Photorheometry allows measurement of a material&#8217;s rheological properties under light stimuli and can reveal the photorheological switching properties of materials. Photo-DSC is a technique to investigate thermodynamic information of materials in darkness and under light irradiation. Lastly, XRD allows studying of microscopic structures of materials. The goal of this article is to clearly present how to prepare and measure the discussed properties of a photorheological material.

This protocol demonstrates the preparation of a photorheological material that exhibits a solid phase, various liquid crystalline phases, and an isotropic liquid phase by increasing temperature. Presented here are methods for measuring the structure-viscoelasticity relationship of the material.

ツイストベンドネマティック液晶の高コントラストと高速フォトレオロジースイッチング

Smart viscoelastic materials that respond to specific stimuli are one of the most attractive classes of materials important to future technologies, such ...

液晶における強誘電分極の磁場調整を測定

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有機マグネットの化学気相堆積、バナジウムテトラ

相図の特徴付け液体担体として磁気ビーズを使用しました

出力偏光測定を通じて非線形偏波回転ファイバレーザにおけるモードロックの自動化

界面湿潤シートの熱力学的成長によって引き起こされる液晶の配向転移

製作手順と磁気応答性ランタノイドイオンのキレートリン脂質アセンブリを設計するための複屈折測定

光応答性液晶の構造ダイナミクスを観察する手法

作製と Van Der waals 力ヘテロエピタキシーに基づくフレキシブル強誘電性要素の測定法

迅速かつ低電圧の色変調のため電気化学コレステリック液晶結晶デバイス

フォトニックナノ構造のスペクトルと角度分解磁気光学特性

ツイストベンドネマティック液晶の高コントラストと高速フォトレオロジースイッチング

液晶における強誘電分極の磁場調整を測定

要約

さらに動画を探す

この動画の章

有機マグネットの化学気相堆積、バナジウムテトラ

相図の特徴付け液体担体として磁気ビーズを使用しました

出力偏光測定を通じて非線形偏波回転ファイバレーザにおけるモードロックの自動化

界面湿潤シートの熱力学的成長によって引き起こされる液晶の配向転移

製作手順と磁気応答性ランタノイド イオンのキレート リン脂質アセンブリを設計するための複屈折測定

光応答性液晶の構造ダイナミクスを観察する手法

作製と Van Der waals 力ヘテロエピタキシーに基づくフレキシブル強誘電性要素の測定法

迅速かつ低電圧の色変調のため電気化学コレステリック液晶結晶デバイス

フォトニックナノ構造のスペクトルと角度分解磁気光学特性

ツイストベンドネマティック液晶の高コントラストと高速フォトレオロジースイッチング

製作手順と磁気応答性ランタノイドイオンのキレートリン脂質アセンブリを設計するための複屈折測定