Competition between ferromagnetism and frustrated antiferromagnetism in quasi 2D Ce-2.15 (Pd1-xAgx)(1.95)In-0.9 alloys

Low temperature thermal and magnetic measurements performed on ferro-magneticl (FM) alloys of composition Ce-2.15(Pd1-xAgx)(1.95)In-0.9 are presented. Pd substitution by Ag depresses T-C(x) from 4.1 K down to 1.1 K for x = 0.5, which is related to the increase of band electrons, with a critical conc...

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Detalles Bibliográficos
Autores: Sereni, Julian Gustavo Renzo, Giovannini, M., Gomez Berisso, Mariano, Gastaldo, Marcelo Fabian
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2016
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/74371
Acceso en línea:http://hdl.handle.net/11336/74371
Access Level:acceso abierto
Palabra clave:Magnetic Frustration
Cerium Compounds
Specific Heat
Entropy
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descripción
Sumario:Low temperature thermal and magnetic measurements performed on ferro-magneticl (FM) alloys of composition Ce-2.15(Pd1-xAgx)(1.95)In-0.9 are presented. Pd substitution by Ag depresses T-C(x) from 4.1 K down to 1.1 K for x = 0.5, which is related to the increase of band electrons, with a critical concentration extrapolated to x(cr) approximate to 0.6. The T-C(x) decrease is accompanied by a weakening of the magnetization of the FM phase. At high temperature (T > 30 K) the inverse magnetic susceptibility reveals the presence of robust magnetic moments (2.56 >= mu(eff) >= 2.4 mu(B)), whereas the low value of the Curie-Weiss temperature theta(P) approximate to -10 K excludes any relevant effect from Kondo screening. The specific heat jump at T-C(x) decreases accordingly, while an anomaly emerges at a fixed temperature T* approximate to 1 K. This unexpected anomaly does not show any associated sign of magnetism checked by AC-susceptibility measurements. Since the total magnetic entropy (evaluated around T = T-C(x = 0)) practically does not change with Ag concentration, the transference of degrees of freedom from the FM component to the non-magnetic T* anomaly is deduced. The origin of this anomaly is attributed to an arising magnetic frustration of the ground state and the consequent entropy bottleneck produced by the divergent increasing of density of excitations at low temperature.