Synthesis, Crystal Structure, and Magnetic Properties of Novel Intermetallic Compounds R2Co2SiC (R = Pr, Nd)

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• 作者：Sixuan Zhou ; Trinath Mishra ; Man Wang ; Michael Shatruk ; Huibo Cao ; Susan E. Latturner
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：June 16, 2014
• 年：2014
• 卷：53
• 期：12
• 页码：6141-6148
• 全文大小：438K
• 年卷期：v.53,no.12(June 16, 2014)
• ISSN：1520-510X

文摘

The intermetallic compounds R₂Co₂SiC (R = Pr, Nd) were prepared from the reaction of silicon and carbon in either Pr/Co or Nd/Co eutectic flux. These phases crystallize with a new stuffed variant of the W₂CoB₂ structure type in orthorhombic space group Immm with unit cell parameters a = 3.978(4) 脜, b = 6.094(5) 脜, c = 8.903(8) 脜 (Z = 2; R₁ = 0.0302) for Nd₂Co₂SiC. Silicon, cobalt, and carbon atoms form two-dimensional flat sheets, which are separated by puckered layers of rare-earth cations. Magnetic susceptibility measurements indicate that the rare earth cations in both analogues order ferromagnetically at low temperature (T_C 鈮?12 K for Nd₂Co₂SiC and T_C 鈮?20 K for Pr₂Co₂SiC). Single-crystal neutron diffraction data for Nd₂Co₂SiC indicate that Nd moments initially align ferromagnetically along the c axis around 12 K, but below 11 K, they tilt slightly away from the c axis, in the ac plane. Electronic structure calculations confirm the lack of spin polarization for Co 3d moments.