Crystal structures of new R3CoAl3Ge2 (R = Gd-Er) quaternary compounds and magnetic properties and lattice thermal expansion of Gd3CoAl3Ge2
Crystal structures of new R3CoAl3Ge2 (R = Gd-Er) quaternary compounds and magnetic properties and lattice thermal expansion of Gd3CoAl3Ge2
复制标题
新型R3CoAl3Ge2（R = Gd-Er）四元化合物的晶体结构及其磁性能和晶格热膨胀
DOI：
10.1016/j.jallcom.2014.11.181
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发表时间：
2015
影响因子：
6.2
通讯作者：
Lin Guoqiang
中科院分区：
文献类型：
--
作者：
He Wei;Zeng Weijing;Lin Guoqiang
用X射线粉末衍射、扫描电子显微镜和X射线能谱等技术研究了新型四元化合物R3 CoAl 3Ge 2（R= Gd-Er）的晶体结构。新化合物R3 CoAl 3Ge 2（R= Gd-Er）具有六方Y3 NiAl 3Ge 2型晶体结构，空间群为P6 <$2m（No.189）.用Rietveld方法对Gd 3CoAl 3Ge 2晶体结构进行了细化.研究了Gd 3CoAl 3Ge 2化合物在298 ~ 688 K温度范围内的晶格热膨胀。计算得到Gd 3CoAl 3Ge 2沿着a和c轴的线性晶格热膨胀系数分别为α a= 8.766× 10− 6 K− 1，α c= 5.534× 10− 6 K− 1. Gd 3 CoAl 3 Ge 2晶胞体积的线性热膨胀系数为α V= 22.84× 10− 6 K− 1。用MPMS SQUID磁强计测量了Gd 3CoAl 3Ge 2在4-300 K温度范围内的磁性。在1 kOe的外磁场下，计算出Gd的有效磁矩μ eff为7.01 μ B/Gd原子，顺磁居里温度θ=− 23.8（3）K。Gd 3CoAl 3Ge 2的磁性测量结果表明，在较低温度下存在反铁磁有序.
The crystal structures of new R 3 CoAl 3 Ge 2 (R= Gd–Er) quaternary compounds were studied by X-ray powder diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy techniques. The novel R 3 CoAl 3 Ge 2 (R= Gd–Er) compounds crystallizes in a hexagonal Y 3 NiAl 3 Ge 2-type structure with space group P 6¯ 2 m (No. 189). The crystal structure of Gd 3 CoAl 3 Ge 2 was refined by Rietveld method. The lattice thermal expansion of the Gd 3 CoAl 3 Ge 2 compound was investigated in a temperature range from 298 K to 688 K. The linear lattice thermal expansion coefficients of Gd 3 CoAl 3 Ge 2 along a and c axes are calculated to be α a= 8.766× 10− 6 K− 1, α c= 5.534× 10− 6 K− 1, respectively. The linear thermal expansion coefficient of the unit cell volume of Gd 3 CoAl 3 Ge 2 is α V= 22.84× 10− 6 K− 1. The magnetic measurement of Gd 3 CoAl 3 Ge 2 was performed in the temperature range of 4–300 K by using MPMS-SQUID magnetometer. The experimental effective magnetic moment (μ eff) is calculated to be 7.01 μ B per Gd atom and paramagnetic Currie temperature θ=− 23.8 (3) K under an applied field of 1kOe. The magnetic measurements of Gd 3 CoAl 3 Ge 2 show antiferromagnetic ordering at lower temperature.