| Full text | |
| Author(s): |
Garcia, F. A.
;
Kaneko, U. F.
;
Granado, E.
;
Sichelschmidt, J.
;
Hoelzel, M.
;
Duque, J. G. S.
;
Nunes, C. A. J.
;
Amaral, R. P.
;
Marques-Ferreira, P.
;
Lora-Serrano, R.
Total Authors: 10
|
| Document type: | Journal article |
| Source: | PHYSICAL REVIEW B; v. 91, n. 22, p. 8-pg., 2015-06-11. |
| Abstract | |
We report a structural-magnetic investigation by x-ray absorption spectroscopy (XAS), neutron diffraction, dc susceptibility (X-dc), and electron spin resonance (ESR) of the 12R-type perovskite BaTi1/2Mn1/2O3. Our structural analysis by neutron diffraction supports the existence of structural trimers with chemically disordered occupancy of Mn4+ and Ti4+ ions, with the valence of the Mn ions confirmed by the XAS measurements. The magnetic properties are explored by combining dc-susceptibility and X-band (9.4 GHz) electron spin resonance, both in the temperature interval of 2 <= T <= 1000 K. A scenario is presented under which the magnetism is explained by considering magnetic dimers and trimers, with exchange constants J(a)/k(B) = 200 (2) K and J(b)/k(B) = 130 (10) K, and orphan spins. Thus, BaTi1/2Mn1/2O3 is proposed as a rare case of an intrinsically disordered S = 3/2 spin gap system with a frustrated ground state. (AU) | |
| FAPESP's process: | 11/22261-5 - Effect of off-stoichiometry in Heusler alloy thin films on spin-dependent tunneling characteristics of X2YZ/MgO magnetic tunnel junction: X-ray absorption spectroscopy and x-ray magnetic circular dichroism |
| Grantee: | Fernando Assis Garcia |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |