arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0903.1607cond-mat.str-el
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单晶R2CoGa8(R = Gd,Tb,Dy,Ho,Er,Tm,Lu和Y)化合物的热行为和输运行为

Thermal and Transport Behavior of Single Crystalline R2CoGa8 (R = Gd, Tb, Dy, Ho, Er, Tm, Lu and Y) Compounds

Devang A. Joshi, A. K. Nigam, S. K. Dhar, A. Thamizhavel

摘要:

研究了R $_{2}$ CoGa $_{8}$系列化合物单晶的电输运和热行为的各向异性。这些化合物均为四方晶系,空间群为P4/mmm。该系列的对应物,即Y $_{2}$ CoGa $_{8}$和Lu $_{2}$ CoGa $_{8}$,显示出与费米能级的低态密度一致的行为。在$_{2}$ $_{8}$中,在$\approx$ 30 K观察到了电荷密度波跃迁的可能性. Gd $_{2}$ CoGa $_{8}$和Er $_{2}$ CoGa $_{8}$在化合物的磁有序温度以上显示出短程相关的存在。在Gd $_{2}$ CoGa $_{8}$的情况下,磁阻对于平行于{[}100{]}和{[}001{]}方向的电流表现出显著的各向异性。具有其它磁性稀土(R = Tb、Dy、Ho和Tm)的化合物显示正常预期的磁性行为,而Dy $_{2}$ CoGa $_{8}$在与Y $_{2}$ CoGa $_{8}$大致相同的温度下显示电荷密度波(CDW)转变的可能性。在结晶电场(CEF)计算的基础上分析了这些化合物的热性质。

英文摘要:

The anisotropy in electrical transport and thermal behavior of single crystalline R$_{2}$CoGa$_{8}$ series of compounds is presented. These compounds crystallize in a tetragonal structure with space gropup P4/mmm. The nonmagnetic counterparts of the series namely Y$_{2}$CoGa$_{8}$ and Lu$_{2}$CoGa$_{8}$show a behavior consistent with the low density of states at the fermi level. In Y$_{2}$CoGa$_{8}$, a possibility of charge density wave transition is observed at $\approx$ 30 K. Gd$_{2}$CoGa$_{8}$ and Er$_{2}$CoGa$_{8}$ show a presence of short range correlation above the magnetic ordering temperature of the compound. In case of Gd$_{2}$CoGa$_{8}$, the magnetoresistance exhibits a significant anisotropy for current parallel to {[}100{]} and {[}001{]} directions. Compounds with other magnetic rare earths (R = Tb, Dy, Ho and Tm) show the normal expected magnetic behavior whereas Dy$_{2}$CoGa$_{8}$ exhibits the possibility of charge density wave (CDW) transition at approximately same temperature as that of Y$_{2}$CoGa$_{8}$. The thermal property of these compounds is analysed on the basis of crystalline electric field (CEF) calculations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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