Commensurate–incommensurate phase transition in TbNi 5

Abstract

Magnetization and neutron diffraction have been measured to study the peculiarities of magnetic ordering of powder and single crystal TbNi 5 samples over the temperature region 2–30 K. Two spontaneous magnetic transitions have been revealed: the second order transition from an incommensurate structure to paramagnetic state ( T p = 24 K ) and the first order transition from an incommensurate structure to a lock-in phase ( T f c = 10 K ). Magnetic satellites are observed at all temperatures below T p. The magnetic structure is described by two wave vectors k 1 = 0 and k 2 = 2 π / c ( 0 , 0 , q ) , where q is equal to 0.0182≈1/55 at 2 K.