Pressure-enhanced direct exchange coupling observed in chromium spinels
Pressure-enhanced direct exchange coupling observed in chromium spinels
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DOI：
10.1103/physrevb.77.224411
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发表时间：
2008-06
影响因子：
3.7
通讯作者：
H. Ueda;Y. Ueda
中科院分区：
文献类型：
--
作者：
H. Ueda;Y. Ueda
Magnetic properties of chromium spinels ${\text{CdCr}}_{2}{\text{O}}_{4}$, ${\text{HgCr}}_{2}{\text{O}}_{4}$, and ${\text{ZnCr}}_{2}{\text{S}}_{4}$ are examined under various pressures. By applying pressure, Curie--Weiss temperatures are reduced indicating enhancement of antiferromagnetic interactions for all these three. For ${\text{HgCr}}_{2}{\text{O}}_{4}$, the field at which magnetic transition to a half moment state occurs raises almost proportional to the Curie--Weiss temperature as pressure increases. This implies nearest-neighbor antiferromagnetic interaction governs the field-induced transition. In addition, we found that the nature of magnetic transition of ${\text{ZnCr}}_{2}{\text{S}}_{4}$ at low temperature is drastically changed from spiral to antiferromagnetic when further nearest-neighbor interactions dominate the nearest neighbor ones, which are suppressed by pressure.
Magnetic properties of chromium spinels ${\text{CdCr}}_{2}{\text{O}}_{4}$, ${\text{HgCr}}_{2}{\text{O}}_{4}$, and ${\text{ZnCr}}_{2}{\text{S}}_{4}$ are examined under various pressures. By applying pressure, Curie--Weiss temperatures are reduced indicating enhancement of antiferromagnetic interactions for all these three. For ${\text{HgCr}}_{2}{\text{O}}_{4}$, the field at which magnetic transition to a half moment state occurs raises almost proportional to the Curie--Weiss temperature as pressure increases. This implies nearest-neighbor antiferromagnetic interaction governs the field-induced transition. In addition, we found that the nature of magnetic transition of ${\text{ZnCr}}_{2}{\text{S}}_{4}$ at low temperature is drastically changed from spiral to antiferromagnetic when further nearest-neighbor interactions dominate the nearest neighbor ones, which are suppressed by pressure.