doi:10.1103/PhysRevB.99.054419engMarcano, N.Algarabel, P.A.Barquín, L.F.Araujo, J.P.Pereira, A.M.Belo, J.H.Magén, C.Morellón, L.Ibarra, M.R.Cluster-glass dynamics of the Griffiths phase in Tb5-xLaxSi2Ge2ART-2019-111231The 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.2019http://zaguan.unizar.es/record/7885810.1103/PhysRevB.99.054419http://zaguan.unizar.es/record/78858oai:zaguan.unizar.es:78858info:eu-repo/grantAgreement/ES/DGA/E26info:eu-repo/grantAgreement/ES/MCIU/MAT2017-83631-C3-Rinfo:eu-repo/grantAgreement/ES/MINECO/MAT2017-82970-C2-2-RPHYSICAL REVIEW B 99, 5 (2019), 054419 [10 pp]by-nchttp://creativecommons.org/licenses/by-nc/3.0/es/info:eu-repo/semantics/openAccess