Resumen: We present measurements of the specific heat, magnetization, magnetocaloric effect, and magnetic neutron diffraction carried out on single crystals of antiferromagnetic Yb3Pt4, where highly localized Yb moments order at TN=2.4 K in zero field. The antiferromagnetic order was suppressed to TN¿0 by applying a field of 1.85 T in the ab plane. Magnetocaloric effect measurements show that the antiferromagnetic phase transition is always continuous for TN>0, although a pronounced step in the magnetization is observed at the critical field in both neutron diffraction and magnetization measurements. These steps sharpen with decreasing temperature, but the related divergences in the magnetic susceptibility are cut off at the lowest temperatures, where the phase line itself becomes vertical in the field-temperature plane. As TN¿0, the antiferromagnetic transition is increasingly influenced by a quantum critical end point, where TN ultimately vanishes in a first-order phase transition. Idioma: Inglés DOI: 10.1103/PhysRevB.84.134409 Año: 2011 Publicado en: Physical Review B. Condensed matter and materials physics 84 (2011), 134409 [9 pp ISSN: 1098-0121 Factor impacto JCR: 3.691 (2011) Categ. JCR: PHYSICS, CONDENSED MATTER rank: 13 / 68 = 0.191 (2011) - Q1 - T1 Tipo y forma: Article (Published version)