Effects of Electric field and Uniaxial Stress on Paramagnetic Spectra in Ferreoelectric Incommensurate phase and its Analyisi by Landau-Ishibashi Theoro.

本文应用Landau-Ishibashi理论讨论了A_2BX_4型晶体中未磁化相和公度相磁共振谱的温度依赖性。考虑到探针亚晶格上的局域电场和单轴应力，我们计算了分裂中的系统温度变化和共振线的形状，清楚地再现了K_2SeO_4：SeO_4^-的实验结果。该装置的特点是将垂直挤压器置于与外加应力垂直的静磁场中旋转。此外，通过冷或热吹气方法，可以很容易地改变样品的温度.利用该装置，我们观察到了铁弹材料LaNbO_4的无公度畴变。本文还讨论了电场和单轴应力对（N（CH_3）_4）_2CoCl_4：Mn^<2+>铁电无公度相顺磁谱的影响。

The Landau-Ishibashi theory was applied to interprete the temperature dependence of the magnetic resonance spectrum in the incommensutate and commensurate phases of A_2 BX_4 type crytals. Taking into accunt the local electric field and uniaxial stress at the probe sub-lattice, we domonstrated the systematic temperature change in the splitting and the shape of resonance lines and clearly reproduced the reported results in K_2 SeO_4 : SeO_4^-, The apparatus for applying uniaxial stress (Pressure and tension) and electric field used with EST spectrometer was developed. This appratus is characterized by perpendicular squeezer which si placed in the static magnetic fiels perpendicular to the applied stress and is rotated. Moreover the sample temperature can easily by changed by the cold ot hot gas blowing method. By using this apparatus we have observed the incommensurate domain switching of ferrroelastic substance such as LaNbo_4. We also obserbed the effect of electric field and uniazial stress on paramagnetic spectra in ferroelectric incommensurate phase in (N(CH_3)_4)_2CoCl_4 :Mn^<2+>.