Magnetic and Magneto‐Optical Properties of Some Rare‐Earth and Yttrium Orthochromites
Magnetic and Magneto‐Optical Properties of Some Rare‐Earth and Yttrium Orthochromites
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DOI：
10.1063/1.1658890
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发表时间：
1970-03
影响因子：
3.2
通讯作者：
K. Tsushima;K. Aoyagi;S. Sugano
中科院分区：
文献类型：
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作者：
K. Tsushima;K. Aoyagi;S. Sugano
根据在TN=141°K以上对YCrO 3的磁化率测量，两个交换常数J1和J2被估计为J1=−8.7 cm−1和J2=−1.0 cm−1。在DyCrO 3中，沿a轴沿着观察到弱铁磁性，TN=146°K。当温度低于5°K时，方向开始向B轴旋转。SmCrO_3中存在自旋重取向，当温度低于重取向温度Tr=35 ~ 40°K时，弱铁磁性方向由c轴向a轴转变。Cr ~（3+）的弱铁磁磁矩的大小在Tr以下迅速减小。使用J1和J2的值，我们估计了YCrO 3中布里渊区表面上高对称点处的磁振子能量。通过将这些磁振子能量与光学观察到的R线边带进行比较，可以将边带指定为一个激子和一个磁振子以及一个激子和两个磁振子的组合激发。观察到的温度依赖性，这些边带支持这一分配。泽...
From the magnetic susceptibility measurement on YCrO3 above TN=141°K, two exchange constants J1 and J2 are estimated to be J1=−8.7 cm−1 and J2=−1.0 cm−1. In DyCrO3 weak ferromagnetism is observed along the a axis, with TN=146°K. When temperature goes below 5°K, the direction begins to rotate towards the b axis. In SmCrO3 a spin reorientation is found. The direction of weak ferromagnetism changes from the c axis to the a axis when the temperature is lowered below the reorientation temperature Tr=35≈40°K. The magnitude of the weak ferromagnetic moment of Cr3+ decreases rapidly below Tr. Using the values of J1 and J2, we estimate the magnon energies at high‐symmetry points on the Brillouin zone surfaces in YCrO3. By comparing these magnon energies with the optically observed sidebands of the R lines, one may assign the sidebands to the combined excitations of one exciton and one magnon, and of one exciton and two magnons. The observed temperature dependence of these sidebands supports this assignment. The ze...