Crystal-field and magnetic properties of the distorted perovskite NdGaO₃

Abstract

Inelastic neutron scattering and magnetic susceptibility measurements have been performed on the distorted perovskite NdGaO3. The magnetic susceptibility data show a Curie-Weiss behaviour with an effective magnetic moment close to 3.6 mu B per mole of Nd ions. No long-range magnetic ordering was detected in the temperature range 2-300 K. The inelastic neutron spectra observed at T=12 K exhibit four peaks of magnetic origin between 11 and 7D meV which can be unambiguously assigned to the complete crystalline-electric-field splitting pattern in the ground-state J multiplet 4I9/2 of the Nd3+ ions. We analysed the spectra in terms of geometrical considerations based on the actual C2 site symmetry of Nd3+. The best agreement between the experimental spectra and the calculated level structure was obtained for a model that takes into account the three nearest-neighbouring coordination polyhedra associated with the O2-, Ga3+ and Nd3+ ions as well as J-mixing between all multiplets of the 4I term. We conclude that single-particle crystal-field theory adequately explains the majority of magnetic and crystal-field properties of NdGaO3.

Role of magnetic exchange energy on charge ordering inR1/3Sr2/3FeOMa1, Yan2, Diallo3 et al. 2011Phys. Rev. B221100View full textAdd to dashboardCite

“…3. These are consistent with previous work, [18,19] and are associated with excitations from the CEF ground state to each of the four excited states. Due to the possible overlap of CEF excitations with spin waves, the phonon scattering contribution and multiple scattering, the separation of the CEF contribution was done by examining both the ω-and Q-dependence of the total cross-section.…”

“…The CEF excitations of NFO can be found via the singleparticle crystal field theory, and is discussed in Refs. [18,19]. The calculation and measurement of the CEF transitions agree with each other very well.…”

Charge, orbital, and magnetic order inNd0.5Ca0.5MnO3<

“…Their magnetic moment is no longer described by g = 8 11 , J = 9 2 as has been already mentioned. Using the experimental data on NdGaO 3 [19], we can estimate their contribution at 40K: M (15T ) ≃ 0.24µ B and M (20T ) ≃ 0.32µ B per formula unit. Experimentally, we get M (15T ) ≃ 3.6µ B and M (20T ) ≃ 3.8µ B .…”

“…It is however quite difficult to estimate exactly the neodymium contribution at these temperature because of crystal field effects on the Nd electronic level. For instance, in NdGaO 3 [19] which has a similar perovskite structure, the J=9/2 electronic level is split into 5 Kramer doublets separated by 137K, 133K, 363K…”

Multifrequency electron spin resonance study of the charge-ordered manganite Nd0.5Ca0.5MnO3

“…1 and 4) shows a strong increase. This low-temperature increase of the susceptibility and shift of the whole ESR spectrum arise either from Nd ions [9] or from modification of the Mn ion magnetic state.…”