Metallurgy, superconductivity and field-dependent magnetic ordering in TbxEr1-xNi2B2C

Superconducting properties and magnetic ordering of pseudoquaternary TbxEr1 -xNi2B2C intermetallic compounds have been investigated by susceptibility, resistivity and magnetization measurements on polycrystalline samples. Tb-r ich compounds display an additional metamagnetic transition which can be su ppressed by magnetic fields as low as 50 mT. A sizable reduction of the sat uration magnetization of pseudoquaternary compounds is observed with a mini mum located near x = 0.5. T-c decreases with increasing Tb fraction up to x approximate to 0.25, where superconductivity breaks down. The effect of co mposition fluctuations within the homogeneity range of the compound leads t o two different types of materials with distinct T-c for a given Tb/Er rati o. A depression of T-N with decreasing Tb content is observed. (C) 1999 Els evier Science B.V. All rights reserved.