Magnetic anisotropy in the paramagnetic phase of TbAl2
Magnetic anisotropy in the paramagnetic phase of TbAl2
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TbAl2 顺磁相的磁各向异性
DOI：
10.1016/0304-8853(84)90326-3
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发表时间：
1984
影响因子：
2.7
通讯作者：
E. W. Lee
中科院分区：
文献类型：
--
作者：
A. D. Moral;J. I. Arnaudas;J. S. Cockaday;E. W. Lee
用转矩磁强计测量了tbal2单晶从居里点以下至170 K直至顺磁相的磁各向异性。在（110）平面内，转矩可以用l (θ) = {Psin 2θ}H2+ {Qsin 2θ +Ssin 4θ}H4+ {Tsin 4θ}H6来描述，其中θ是磁化矢量与[001]轴形成的夹角。第一项（inH2）被解释为由具有轴对称的缺陷阵列产生。第二项（inH4）和第三项（inH6）来自各向异性的第四和第六阶张量顺磁化率。另一方面，如果用90-170 K范围内的有效常规各向异性常数sk1和k2来描述各向异性，则发现这两个常数在居里温度范围内连续变化，并且在顺磁范围内[111]方向仍然是容易方向。各向异性测量表明它们是磁性晶体中宏观缺陷水平的敏感指标。
The magnetic anisotropy of a single crystal of TbAl2has been measured by torque magnetometry from below the Curie point up to 170 K, well into the paramagnetic phase. Within a (110) plane the torque can be described by the expressionL(θ) = {Psin 2θ}H2+ {Qsin 2θ +Ssin 4θ}H4+ {Tsin 4θ}H6, where θ is the an gle formed by the magnetization vector with a [001] axis. The first term (inH2) is interpreted as produced by arrays of defects with axial symmetry. The second (inH4) and third (inH6) terms arise from anisotropic fourth and sixth rank tensor paramagnetic susceptibilities. On the other hand if the anisotropy is described in terms of effective conventional anisotropy constantsK1andK2within the temperature range 90–170 K it is found that both constants change continuously across the Curie temperature and furthermore the [111] direction remains the easy direction in the paramagnetic range. Anisotropy measurements reveal themselves as a sensitive indicator of the level of macroscopic defects in magnetic crystals.