High-Field ESR and Magnetization of the Triangular Lattice Antiferromagnet NiGa2S4
High-Field ESR and Magnetization of the Triangular Lattice Antiferromagnet NiGa2S4
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DOI：
10.1143/jpsj.79.054710
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发表时间：
2010-02
影响因子：
1.7
通讯作者：
H. Yamaguchi;S. Kimura;M. Hagiwara;Y. Nambu;S. Nakatsuji;Y. Maeno;A. Matsuo;K. Kindo
中科院分区：
文献类型：
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作者：
H. Yamaguchi;S. Kimura;M. Hagiwara;Y. Nambu;S. Nakatsuji;Y. Maeno;A. Matsuo;K. Kindo
报道了准二维三角晶格反铁磁体NiGa 2S 4的电子自旋共振（ESR）和高磁场下磁化强度的实验和分析结果.从ESR谱线宽度的温度演化中发现，在23 ~ 8.5K之间，Z2涡旋对自旋关联的发展有明显的扰动。在T v =8.5 K以下，基于57°螺旋自旋序的自旋波计算很好地解释了ESR共振场的频率依赖性和H_（10）c和H_（10）c的高场磁化过程，尽管H_（10）c在高场的磁化与计算的不同。此外，我们解释了与场无关的比热与T2依赖的相同的自旋波计算，但比热的大小是远远小于观察到的。单离子各向异性常数D / k B =0.8 K与T_V（λ/ a）~（-2）=0.3-0.4 K是同一数量级。
We report the experimental and analytical results of electron spin resonance (ESR) and magnetization at high magnetic fields of up to about 68 T of the quasi two-dimensional triangular lattice antiferromagnet NiGa 2 S 4 . From the temperature evolution of the ESR absorption linewidth, we find a distinct disturbance of the development of the spin correlation by Z 2 -vortices between 23 and 8.5 K. Below T v =8.5 K, spin-wave calculations based on a 57° spiral spin order well explain the frequency dependence of the ESR resonance fields and high-field magnetization processes for H ∥ c and H ⊥ c , although the magnetization for H ⊥ c at high fields is different from the calculated one. Furthermore, we explain the field-independent specific heat with a T 2 dependence by the same spin-wave calculation, but the magnitude of specific heat is much less than the observed one. The single ion anisotropy constant D / k B =0.8 K is the same order of T V (ξ/ a ) -2 =0.3–0.4 K where ξ and a are the correlation length and ...