Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA.
J Phys Condens Matter. 2010 Oct 27;22(42):426002. doi: 10.1088/0953-8984/22/42/426002. Epub 2010 Oct 7.
Single crystals of CeM₂ and GdM₂ (M = Ag, Al, and Si) were grown by the flux growth technique and characterized by means of single crystal x-ray diffraction, magnetic susceptibility, resistivity, and heat capacity measurements. CeM₂ and GdM₂ crystallize in the tetragonal I4(1)/amd space group with the α-ThSi₂ structure type with lattice parameters a ~4.2 Å and c ~14.4 Å. Curie-Weiss behavior is observed for both analogues with CeM₂ ordering first ferromagnetically at 11 K with a second antiferromagnetic transition at 8.8 K while GdM₂ orders antiferromagnetically at 24 K. Heat capacity measurements on CeM₂ show two magnetic transitions at 10.8 and 8.8 K with an electronic specific heat coefficient, γ(0), of ~53 mJ K(-2) mol(-1). The entropy at the magnetic transition is less than the expected Rln2 for CeM₂, reinforcing the assertions of an enhanced mass state and Kondo behavior being observed in the resistivity.
采用熔剂生长法生长了 CeM₂ 和 GdM₂（M = Ag、Al 和 Si）的单晶，并通过单晶 X 射线衍射、磁化率、电阻率和热容测量对其进行了表征。CeM₂ 和 GdM₂ 分别以四方 I4(1)/amd 空间群和 α-ThSi₂结构类型结晶，晶格参数 a4.2 Å 和 c14.4 Å。两种类似物均表现出居里-外斯行为，CeM₂ 首先在 11 K 下铁磁有序，随后在 8.8 K 下发生第二次反铁磁转变，而 GdM₂ 在 24 K 下反铁磁有序。CeM₂ 的热容测量显示在 10.8 和 8.8 K 处有两个磁转变，电子比热系数 γ(0)约为 53 mJ K(-2) mol(-1)。磁转变处的熵小于 CeM₂ 的预期 Rln2，这加强了在电阻率中观察到增强质量态和康普顿行为的说法。
