Quasi‐one‐dimensional antiferromagnetism in MnCl2⋅H2O
| Autor: | J. A. Lukin, Gary C. DeFotis, S. A. Friedberg |
|---|---|
| Rok vydání: | 1991 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 69:5807-5809 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.347884 |
| Popis: | Recent magnetic susceptibility measurements on polycrystalline MnCl2⋅H2O indicate that it behaves like a quasi‐one‐dimensional antiferromagnet. The heat capacity of this compound has now been measured between ∼0.5 and 80 K in a liquid‐3He‐cooled vacuum calorimeter. Cp exhibits a large, sharp λ‐type peak at TN = 2.18 ± 0.01 K marking the onset of long‐range spin order. The critical entropy S(TN) is found to be ∼0.40R ln 6, confirming the short‐range, low‐dimensional nature of most of the spin ordering. An anisotropic elastic continuum model has been used to calculate the contribution of lattice vibrations to Cp. The data above ∼3 K are well represented by this model (with suitable choice of three parameters) plus the theoretical heat capacity of the 1D Heisenberg antiferromagnet with S =5/2 and exchange constant J/k=−0.45 K. Below ∼ 0.7TN, the magnetic part of Cp is well described by an anisotropic 3D spin‐wave model with Jz/k = J/k = −0.45 K, Jx/k = Jy/k = −0.015 K, and an anisotropy field HA ≊ 3.3 kOe. T... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|