Solution growth of the Gd–Cu–Al systems in the low-gadolinium concentration range

Abstract

Abstract Solution growth of Gd–Cu–Al resulted in the formation of single crystals of GdCu4Al8 with tetragonal ThMn12-type structure (a = 8.751 Å, c = 5.148 Å), Gd2Cu9.4 – 6.7Al7.6 – 10.3 with hexagonal Th2Zn17-type structure (a = 8.83 Å, c = 1.28 Å), and Gd(Cu, Al)4 with orthorhombic CeNi2+x Sb2 – x -type structure. An antiferromagnetic ordering of GdCu4Al8 was found below 35 K, which is in agreement with the previously reported TN = 35 K and TN = 32 K measured on polycrystalline samples. In the temperature range 50 – 320 K the magnetic susceptibility χ follows the Curie–Weiss law with μeff = 7.8 μB/f. u. and θp = – 17 K for B c, μeff = 7.9 μB/f. u. and θp = – 18 K for B ⊥ c. The a-axis is the easy magnetization direction. The Gd(Cu, Al)4 and Gd(Cu, Al)4 compounds order antiferromagnetically below TN = 35 K and TN = 31 K, respectively.