title: Parimagnetism in HoCo2 and TmCo2.
abstract: X-ray magnetic circular dichroism (XMCD), longitudinal (χac) and transverse (TS) ac magnetic susceptibility have been measured in the RCo2 series (R = Ho, and Tm) as a function of temperature and applied magnetic field. We show that parimagnetism is a general behavior among the RCo2 ferrimagnetic series (R being a heavy rare-earth ion). XMCD results supply evidence of the presence of two compensation temperatures above Tc, defining two different parimagnetic configurations, which is a fully unexpected result. The inverse χ'ac curve exhibits a small anomaly which vanishes under low applied magnetic fields. The combination of TS and XMCD measurements allows one to depict new magnetic phase diagrams for these compounds of the RCo2 series. A new scenario allowing one to understand the observed phenomenology as a Griffiths phase-like behavior is proposed, where the amorphous RCo2 represents the undiluted system case.
authors.affiliation: Departamento de Física de la Materia Condensada and Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain.
authors.forename: C M
authors.initials: CM
authors.lastname: Bonilla
authors.forename: J
authors.initials: J
authors.lastname: Herrero-Albillos
authors.forename: A I
authors.initials: AI
authors.lastname: Figueroa
authors.forename: C
authors.initials: C
authors.lastname: Castán-Guerrero
authors.forename: J
authors.initials: J
authors.lastname: Bartolomé
authors.forename: I
authors.initials: I
authors.lastname: Calvo-Almazán
authors.forename: D
authors.initials: D
authors.lastname: Schmitz
authors.forename: E
authors.initials: E
authors.lastname: Weschke
authors.forename: L M
authors.initials: LM
authors.lastname: García
authors.forename: F
authors.initials: F
authors.lastname: Bartolomé
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D002942:Circular Dichroism; D003198:Computer Simulation; D006695:Holmium / Q000737:chemistry*; D060526:Magnetic Fields; D059346:Magnets / Q000737:chemistry*; D008956:Models, Chemical; D012815:Signal Processing, Computer-Assisted; D013696:Temperature; D013932:Thulium / Q000737:chemistry*; D014965:X-Rays
chemical_list: D002245:Carbon Dioxide; D013932:Thulium; D006695:Holmium