Cluster-glass dynamics of the Griffiths phase in Tb5-xLaxSi2Ge2

Marcano, N. (Universidad de Zaragoza) ; Algarabel, P.A. (Universidad de Zaragoza) ; Barquín, L.F. ; Araujo, J.P. ; Pereira, A.M. ; Belo, J.H. ; Magén, C. (Universidad de Zaragoza) ; Morellón, L. (Universidad de Zaragoza) ; Ibarra, M.R. (Universidad de Zaragoza)

Resumen: The static magnetization and dynamic susceptibility responses of the cluster system within a Griffiths phase of the magnetocaloric compound Tb5-xLaxSi2Ge2 (x=0.075) have been investigated. A novel cluster-glass state within the Griffiths phase is formed at a characteristic freezing temperature where short-range ferromagnetic correlations set in the paramagnetic regime. Ferromagneticlike correlations are built up at around 155 K, which suddenly become frozen at a lower temperature ~140K, thus in analogy with a reentrant spin glass behavior. The ac susceptibility near the freezing temperature follows a critical slowing down process characterized by t0=10-13s and dynamic exponents z¿~6 and ß~0.4, similar to well-known spin glass systems. The nonlinear ac susceptibility analysis shows clearly the existence of a transition associated to the reentrant behavior. The origin of the intermediate cluster-glass phase inside the Griffiths phase is proposed to be the result of a combination of short-ranged RKKY intralayer positive exchange interactions between rare-earth Tb3+ ions and antiferromagnetic exchange between adjacent interlayers involving Si and Ge atoms in connection to the Tb3+ atoms.

Idioma: Inglés

DOI: 10.1103/PhysRevB.99.054419

Año: 2019

Publicado en: PHYSICAL REVIEW B 99, 5 (2019), 054419 [10 pp]
ISSN: 2469-9950

Factor impacto SCIMAGO: 1.811 - Electronic, Optical and Magnetic Materials (Q1) - Condensed Matter Physics (Q1)

Financiación: info:eu-repo/grantAgreement/ES/DGA/E26
Financiación: info:eu-repo/grantAgreement/ES/MCIU/MAT2017-83631-C3-R
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2017-82970-C2-2-R

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)