Abstract
In this paper we report the detailed study of magnetic phase diagrams, low-temperature magnetic structures, and the magnetic field effect on the electrical resistivity of the binary intermetallic compound Tb3Ni. The incommensurate magnetic structure of the spin-density-wave type described with magnetic superspace group P1121/a1′(ab0)0ss and propagation vector kIC=[0.506,0.299,0] was found to emerge just below Néel temperature TN=61 K. Further cooling below 58 K results in the appearance of multicomponent magnetic states: (i) a combination of k1=[1/2,1/2,0] and kIC in the temperature range 51<T<58 K; (ii) a mixed magnetic state of kIC, k1, and k2=[1/2,1/4,0] with the partially locked-in incommensurate component in the temperature range 48<T<51 K; and (iii) a low-temperature magnetic structure that is described by the intersection of two isotropy subgroups associated with the irreducible representations of two coupled primary order parameters (OPs) k2=[1/2,1/4,0] and k3=[1/2,1/3,0] and involves irreducible representations of the secondary OPs k1=[1/2,1/2,0] and k4=[1/2,0,0] below 48 K. An external magnetic field suppresses the complex low-temperature antiferromagnetic states and induces metamagnetic transitions towards a forced ferromagnetic state that are accompanied by a substantial magnetoresistance effect due to the magnetic superzone effect. The forced ferromagnetic state induced after application of an external magnetic field along the b and c crystallographic axes was found to be irreversible below 3 and 8 K, respectively.
