Critical Behavior of CsVBr3 and RbVBr3
Critical Behavior of CsVBr3 and RbVBr3
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CsVBr3 和 RbVBr3 的临界行为
DOI：
10.1143/jpsj.63.3169
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发表时间：
1994
影响因子：
1.7
通讯作者：
S. Matsuo
中科院分区：
文献类型：
--
作者：
Hidekazu Tanaka;H. Nakano;S. Matsuo
利用c平面外场的磁化率测量，研究了平面反铁磁体csvbr3和rbvbr3的磁相图。具有csnicl3结构的csvbr3表现出与csmnbr3相同的四晶行为（tn =20.3 K）。在H≈8t时，由于强链内交换耦合，中间相的间隔仅为～ 1k。化学单元胞增大到\(\sqrt{3}a\), \(\sqrt{3}a, c\)的rbvbr3由于c面交换相互作用的不平等，在零场中经历了t1 =28.1 K和T N2 =21.0 K的两次跃迁。零场过渡点（t0）附近的两个相界描述为h2∝∣T - t0∣φ，单指数φ≈0.8 （csvbr3）和φ≈1.0 （rbvbr3）。csvbr3的交叉指数φ小于n =2手性普适类的预测值φ≈1.04。
The magnetic phase diagrams of planar antiferromagnets CsVBr 3 and RbVBr 3 have been investigated by susceptibility measurements with the external field applied in the c -plane. CsVBr 3 with the CsNiCl 3 structure shows tetracritical behavior ( T N =20.3 K) as observed in CsMnBr 3 . The interval of the intermediate phase is only ∼ 1 K at H ≈8 T because of the strong intrachain exchange coupling. RbVBr 3 with a chemical unit cell enlarged to \(\sqrt{3}a\), \(\sqrt{3}a, c\) undergoes two transitions at T N1 =28.1 K and T N2 =21.0 K in zero field due to the inequality of exchange interactions in the c-plane. Both phase boundaries near the zero field transition points ( T 0 ) are described as H 2 ∝∣ T - T 0 ∣ φ with a single exponent φ≈0.8 for CsVBr 3 and φ≈1.0 for RbVBr 3 . The crossover exponent φ for CsVBr 3 is smaller than the value φ≈1.04 predicted for the n =2 chiral universality class.