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)