Anisotropic behavior of magnetic and transport properties in CePdSb and CePtSb
Anisotropic behavior of magnetic and transport properties in CePdSb and CePtSb
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DOI：
10.1143/jpsj.68.613
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发表时间：
1999-02-01
影响因子：
1.7
通讯作者：
Suzuki, T
中科院分区：
文献类型：
--
作者：
Katoh, K;Takabatake, T;Suzuki, T
使用单晶样品对六方铁磁体 CeTSb (T = Pd,Pt) 和同结构化合物 LaTSb 进行了电阻率 rho、霍尔系数 R-H、磁化率 chi、磁化强度、比热 C 和磁阻的测量。 Ce 化合物和 La 化合物均观察到 rho 的强各向异性，rho(c) > rho(a)。然而，CeTSb 的 R-H(T) 在 H//a 和 H//c 之间没有表现出强的各向异性。晶体电子场模型很好地再现了 Ce 化合物的 chi(T) 各向异性行为。 chi(T)的分析表明CePdSb中沿c轴的铁磁交换相互作用比CePtSb中的强得多。磁化测量表明，CePdSb 和 CePtSb 的饱和磁矩分别为 1.32 mu(B) 和 0.91 mu(B)，处于铁磁态时位于 c 面内。 CePdSb 的 C(T) 除了 10K 附近的宽峰外，在 T-C = 17.5 K 处显示出明显的跳跃。这些结果表明，CePdSb 中在 T-C = 17.5 K 时出现沿 c 轴的一维磁序，而三维磁序仅在 10 K 以下发展。发现 CePdSb 和 CePtSb 的 rho(c) 分别在 8 K 和 6 K 以下增加，两种化合物的 R-H(H//a; I//c) 也在 10 K 以下增加。与通常的铁磁体不同，铁磁状态下的横向和纵向磁阻对于 H//a 来说很大程度上是正值。这些不寻常的传输特性可能归因于当前系统铁磁态下的异常自旋动力学。
Measurements of resistivity rho, Hall coefficient R-H, magnetic susceptibility chi, magnetization, specific heat C and magnetoresistance have been performed on the hexagonal ferromagnets CeTSb (T = Pd,Pt) and the isostructural compounds LaTSb using single crystalline samples. Strong anisotropy in rho, rho(c) > rho(a), was observed for both the Ce compounds as well as the La compounds. However, R-H(T) for CeTSb does not exhibit strong anisotropy between H//a and H//c. The anisotropic behavior of chi(T) for the Ce compounds is well reproduced by the crystalline electronic-field model. The analysis of chi(T) suggests that the ferromagnetic exchange interaction along the c axis in CePdSb is much stronger than that in CePtSb. Magnetization measurements reveal that the saturated magnetic moments of 1.32 mu(B) and 0.91 mu(B) for CePdSb and CePtSb lie within the c plane in the ferromagnetic state. The C(T) for CePdSb shows a clear jump at T-C = 17.5 K in addition to a broad peak around 10K. These results suggest that one dimensional magnetic order along the c axis occurs in CePdSb at T-C = 17.5 K and three-dimensional order develops only below 10 K. It is found that rho(c) increases below 8 K and 6 K for CePdSb and CePtSb, respectively, and R-H(H//a; I//c) also increases below 10 K for both compounds. Unlike usual ferromagnets, the transverse and longitudinal magnetoresistances in the ferromagnetic states are largely positive for H//a. These unusual transport properties may be ascribed to the anomalous spin dynamics in the ferromagnetic state of the present systems.