Inelastic neutron scattering investigation of the crystal field excitations of NdCo₅

Author(s)

Passos, F. de Almeida ; Nilsen, G. J. ; Patrick, C. E. ; Le, M. D. ; Balakrishnan, G. ; Kumar, Santosh ; Thamizhavel, A. ; Cornejo, D. R. ; Jimenez, J. Larrea

• Document type: Journal article
• Source: PHYSICAL REVIEW B; v. 108, n. 17, p. 8-pg., 2023-11-07.

Abstract

We present an inelastic neutron scattering study of the crystal electric field (CEF) levels in the intermetallic ferrimagnets RECo5 (RE=Nd and Y). In NdCo5, measurements at 5K reveal two levels at approximately 28.9 and 52.9 meV. Crystal-field calculations including the exchange field B-exc from the Co sites account for both of these, as well as the spectrum at temperatures above the spin-reorientation transition at similar to 280 K. In particular, it is found that both a large hexagonal crystal field parameter A(6)(6)< r(6)> and B-exc are required to reproduce the data, with the latter having a much larger value than that deduced from previous computational and experimental studies. Our study sheds light on the delicate interplay of terms in the rare-earth Hamiltonian of RECo5 systems, and is therefore expected to stimulate further experimental and computational work on the broader family of rare-earth permanent magnets. (AU)

• FAPESP's process: 19/24711-0 - Uncovering novel states of quantum matter in strongly correlated spin systems under extreme conditions
• Grantee: Fernando de Almeida Passos
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 18/08845-3 - An investigation into topological and exotic quantum states under extreme conditions (InvestInTopQuantEx)
• Grantee: Julio Antonio Larrea Jimenez
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 19/24797-1 - Neutron and bulk investigations of nanocrystalline Sm$_{1-x}$y$_{x}$Co$_{5}$: a new route towards hard permanent magnets
• Grantee: Julio Antonio Larrea Jimenez
• Support Opportunities: Research Grants - Visiting Researcher Grant - International