Phase Transition from Antiferromagnetic to Metallic State in La 2- x Sr x NiO 4+ δ
1992; Physical Society of Japan; Volume: 61; Issue: 4 Linguagem: Inglês
10.1143/jpsj.61.1182
ISSN1347-4073
Autores Tópico(s)Magnetic and transport properties of perovskites and related materials
ResumoWe have measured 139 La nuclear magnetic resonance and nuclear quadrupole resonance in La 2- x Sr x NiO 4+δ at low temperatures (1.4–4.2 K) in order to investigate the change in the magnetic and electronic structures when Sr is doped into La 2 NiO 4+δ . The Sr-substituted compound shows an antiferromagnetic order up to x ∼1 with a monotonous decrease in the internal magnetic field H int at the La sites. In the high Sr-content region at x ∼1, we find a phase transition to a nonmagnetic state where H int disappears. In the nonmagnetic state, the Knight shift of 139 La is about -1.5% for x =1.0 and -1.0% for x =1.3, and the 139 La spin-lattice relaxation time T 1 follows the Korringa relation of T 1 T ∼7.6 sK for x =1.0 and ≃48 sK for x =1.3, which indicates that the system is in a normal metallic state.
Referência(s)