Eur. Phys. J. B 30, 313-318 (2002)
https://doi.org/10.1140/epjb/e2002-00384-5

Evolution of magnetism in U(Ni_1-xPd_x)₂Si₂ single crystals

¹ Department of Electronic Structures, Charles University, Ke Karlovu 5, 121 16 Prague 2, The Czech Republic
² Institute of Physics ASCR, Na Slovance 2, 182 21 Prague 8, The Czech Republic
³ Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan

Corresponding author: ^a sech@mag.mff.cuni.cz

Received: 28 March 2002
Revised: 8 August 2002
Published online: 19 December 2002

Abstract

Single crystals of U(Ni_1-xPd_x)₂Si₂ with x = 0.05, 0.09 and 0.135 have been grown. Magnetization and electrical resistivity measurements were performed in a wide range of temperatures and magnetic fields in order to study stability of magnetic phases in the solid solutions between UNi₂Si₂ and UPd₂Si₂ with a special emphasis on the type of ground state. In UPd₂Si₂ the simple AFI-type antiferromagnetic structure of U moments is observed at low temperatures. UNi₂Si₂ adopts the uncompensated AF structure (UAF) with the ++- stacking of U moments along the c-axis and consequently this compound exhibits a spontaneous magnetization corresponding to 1/3 of the U moment. The substitution of Pd for Ni leads to a rapid decay of the spontaneous magnetization. The evolution of magnetization and electrical resistivity behavior with Pd doping is tentatively attributed to the coexistence of the AF-I and UAF phases in the ground state of U(Ni_0.91Pd_0.09)₂Si₂ and U(Ni_0.865Pd_0.135)₂Si₂. In this scenario, the volume fraction of the AF-I phase rapidly grows with Pd doping on account of the UAF. At lowest temperatures an irreversible transition to the UAF phase is observed when a sufficiently high magnetic field is applied along the c-axis.