Ultralow-frequency elastic response in KMn1-xCaxF3
Ultralow-frequency elastic response in KMn1-xCaxF3
复制标题
KMn1-xCaxF3 中的超低频弹性响应
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
E. Salje
中科院分区：
文献类型：
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作者：
W. Schranz;A. Tröster;A. Kityk;P. Sondergeld;E. Salje
我们提出了新的低频（0.1 Hz-50 Hz）测量KMn 1 − x Ca x F3（x = 0，0.003，0.018）的复弹性磁化率。在纯KMnF_3中，在低于Tc = 186 K时，发现了一个超低弛豫过程，并用改进的热扩散模型进行了解释.与SrTiO_3和纯KMnF_3的情况相比，我们发现在掺Ca量为0.3%的混晶中出现了铁弹畴冻结现象。分散体显示科尔-戴维森的行为与一个额外的对数低频率的贡献，在与随机分布的杂质的晶体中的弹性界面的弱钉扎的理论结果一致。
We present novel low-frequency (0.1 Hz–50 Hz) measurements of the complex elastic susceptibility of KMn 1 − x Ca x F3 (x = 0, 0.003, 0.018). An ultraslow relaxational process in pure KMnF3 just below Tc = 186 K is discovered and explained by a refined heat diffusion model. In addition, a giant softening (superelasticity) due to domain wall motion is found. In contrast to the case of SrTiO3 and also of pure KMnF3, we find a ferroelastic domain freezing in the mixed crystals with 0.3% Ca substitution. The dispersion displays a Cole-Davidson–like behaviour with an additional logarithmic low-frequency contribution in agreement with the theoretical results for weak pinning of elastic interfaces in crystals with randomly distributed impurities.