Domain walls have distinct properties from the bulk, and tailoring them to suit the needs for device applications is critical. Tungsten trioxide, ${\mathrm{WO}}_3$, is of great interest for device applications that make use of domain wall properties; it exhibits a phenomenologically rich sequence of phase transitions, virtually all of which are ferroelastic in character, resulting in many sets of domain walls at low temperatures, each with their own unique properties. Domain wall motion and its contribution to the piezoelectric response have been investigated in ${\mathrm{WO}}_3$ from 300 to 180 K using resonant ultrasound spectroscopy (RUS) and resonant piezoelectric spectroscopy (RPS), which showed that the $P{2}_1/n,P\overline{1}$, and $P{2}_1/c$ phases give a piezoelectric response despite the bulk being nominally centrosymmetric. Second harmonic generation (SHG) confirmed that polarity was strongest within the domain walls, and additional weak signals were found in the domains. Domain wall mobility was investigated in the $Pbcn,P{2}_1/n$, and $P{2}_1/c$ phases from 685 to 5 K. Domain walls in the $P{2}_1/n$ and $P\overline{1}$ were more mobile than those in the $Pbcn$ and $P{2}_1/c$ structures, and soon after the $P\overline{1}\to P{2}_1/c$ transition the walls become pinned at $\sim 140\mathrm{K}$.

中文翻译：

---

三氧化钨中的畴壁动力学：极性畴壁的证据


畴壁具有与本体不同的特性，对其进行定制以满足设备应用的需求至关重要。三氧化钨， ${\mathrm{WO}}_3$ ，对于利用畴壁特性的设备应用非常感兴趣；它表现出现象学上丰富的相变序列，几乎所有相变都具有铁弹性特征，从而在低温下产生许多组磁畴壁，每个磁畴壁都有自己独特的特性。畴壁运动及其对压电响应的贡献已在 ${\mathrm{WO}}_3$ 使用共振超声光谱 (RUS) 和共振压电光谱 (RPS) 从 300 K 到 180 K，结果表明 $P{2}_1/n,P\overline{1}$ ， 和 $P{2}_1/c$ 尽管体积名义上是中心对称的，但相仍给出压电响应。二次谐波发生（SHG）证实了磁畴壁内的极性最强，并且在磁畴中发现了额外的微弱信号。研究了畴壁迁移率 $Pbcn,P{2}_1/n$ ， 和 $P{2}_1/c$ 从 685 到 5 K 的阶段。域壁 $P{2}_1/n$ 和 $P\overline{1}$ 比那些在 $Pbcn$ 和 $P{2}_1/c$ 结构，并且不久之后 $P\overline{1}\to P{2}_1/c$ 过渡墙壁被固定在 $\sim 140\mathrm{K}$ 。