2011/11/22 by M. Stingaciu, Marian Stingaciu, H. Luetkens +12
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic and transport properties of perovskites and related materials #Multiferroics and related materials #Optical properties and cooling technologies in crystalline materials #Strongly Correlated Electrons (cond-mat.str-el) #cond-mat.str-el
paper · pdf · doi:10.48550/arxiv.1111.5232
arxiv created 2011/11/22 · openalex publication_date 2011/11/22 · arxiv updated 2011/11/23 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The magnetic properties of polycrystaline La0.5Ba0.5CoO2.5+d (d = 0.44 and 0.485) where investigated using muon spin relaxation and bulk magnetization experiments. Below a Curie temperature of TC = 160 K and 180 K, respectively, a magnetic phase with a macroscopic ferromagnetic moment forms. muSR proves that the full volume inhomogeneously orders at TC but that there is microscopically a phase separation into phase volumes possessing a fully static and a slow magnetic dynamic behavior. A peak in the dynamic relaxation rate 35 K respectively 55 K below the Curie temperature indicates the freezing of spin components. The spin fluctuations are thermally activated with a typical Jahn-Teller like phonon energy of Ea = 340 K. Together with co-operative Jahn-Teller distortions appearing below the spin freezing temperature, this points to a strong magneto elastic coupling as the cause for the magnetic fluctuations and the spin freezing.