Synthesis, Structure, and Physical Properties of Ln(Cu,Al,Ga)13鈥?i>x (Ln = La鈥揚r, and Eu) and Eu(Cu,Al)13鈥?i>x

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• 作者：W. Adam Phelan ; Michael J. Kangas ; Gregory T. McCandless ; Brenton L. Drake ; Neel Haldolaarachchige ; Liang L. Zhao ; Jiakui K. Wang ; Xiaoping P. Wang ; David P. Young ; Emilia Morosan ; Christina Hoffmann ; Julia Y. Chan
• 刊名：Inorganic Chemistry
• 出版年：2012
• 出版时间：October 1, 2012
• 年：2012
• 卷：51
• 期：19
• 页码：10193-10202
• 全文大小：465K
• 年卷期：v.51,no.19(October 1, 2012)
• ISSN：1520-510X

文摘

Ln(Cu,Al,Ga)_13鈥?i>x (Ln = La鈥揚r, and Eu; x 0.2) were synthesized by a combined Al/Ga flux. Single crystal X-ray and neutron diffraction experiments revealed that these compounds crystallize in the NaZn₁₃ structure-type (space group Fm3̅c) with lattice parameters of a 12 脜, V 1600 脜, and Z 8. Our final neutron models led us to conclude that Cu is occupationally disordered on the 8b Wyckoff site while Cu, Al, and Ga are substitutionally disordered on the 96i Wyckoff site of this well-known structure-type. The magnetic susceptibility data show that Ce(Cu,Al,Ga)_13鈥?i>x and Pr(Cu,Al,Ga)_13鈥?i>x exhibit paramagnetic behavior down to the lowest temperatures measured while Eu(Cu,Al,Ga)_13鈥?i>x displays ferromagnetic behavior below 6 K. Eu(Cu,Al)_13鈥?i>x was prepared via arc-melting and orders ferromagnetically below 8 K. The magnetocaloric properties of Eu(Cu,Al,Ga)_13鈥?i>x and Eu(Cu,Al)_13鈥?i>x were measured and compared. Additionally, an enhanced value of the Sommerfeld coefficient (纬 = 356 mJ/mol-K²) was determined for Pr(Cu,Al,Ga)_13鈥?i>x. Herein, we present the synthesis, structural refinement details, and physical properties of Ln(Cu,Al,Ga)_13鈥?i>x (Ln = La鈥揚r, and Eu) and Eu(Cu,Al)_13鈥?i>x.