A1 Refereed original research article in a scientific journal
Electronic and magnetic phase diagram of polycrystalline Gd1-xCaxMnO3 manganites
Authors: Beiranvand A, Tikkanen J, Huhtinen H, Paturi P
Publisher: ELSEVIER SCIENCE SA
Publication year: 2017
Journal: Journal of Alloys and Compounds
Journal name in source: JOURNAL OF ALLOYS AND COMPOUNDS
Journal acronym: J ALLOY COMPD
Volume: 720
First page : 126
Last page: 130
Number of pages: 5
ISSN: 0925-8388
eISSN: 1873-4669
DOI: https://doi.org/10.1016/j.jallcom.2017.05.231
Abstract
Based on the structural and magnetoresistive properties of Gd1-xCaxMnO3 (GCMO) (0 <= x <= 1) polycrystalline manganites, the magnetic phase diagram of GCMO is deduced. The results show that all of the compounds are ferrimagnetic in the ground state due to polarization of the large magnetic moments of Gd in the opposite direction of Mn ions. However, even disregarding the ordering of the Gd spins in the applied magnetic field direction, the series exhibit complicated magnetic behavior below magnetic ordering temperature (T-C or T-N). In the hole doped region x <= 0. 5, Mn ions order ferromagnetically. In the middle doping region (0.5 <= x <= 0.7), charge ordering can be observed above T-N and, below T-N, Mn ions are in antiferromagnetic state which is more obvious in the case with x = 0.8. In the electron doped region 0.8 <= x <= 0.9, Mn ions reveal magnetic cluster glass properties. Except for x = 0.9, which exhibits degenerate semiconductive behavior, the temperature dependence of resistance shows insulating behavior for all other GCMO concentrations. This can be associated with the small average ionic radius of rare earth cations and colossal magnetoresistance (CMR) is observed for GCMO with x = 0.8 and x = 0.9 when the applied magnetic field exceeds 9 T. (C) 2017 Elsevier B.V. All rights reserved.
Based on the structural and magnetoresistive properties of Gd1-xCaxMnO3 (GCMO) (0 <= x <= 1) polycrystalline manganites, the magnetic phase diagram of GCMO is deduced. The results show that all of the compounds are ferrimagnetic in the ground state due to polarization of the large magnetic moments of Gd in the opposite direction of Mn ions. However, even disregarding the ordering of the Gd spins in the applied magnetic field direction, the series exhibit complicated magnetic behavior below magnetic ordering temperature (T-C or T-N). In the hole doped region x <= 0. 5, Mn ions order ferromagnetically. In the middle doping region (0.5 <= x <= 0.7), charge ordering can be observed above T-N and, below T-N, Mn ions are in antiferromagnetic state which is more obvious in the case with x = 0.8. In the electron doped region 0.8 <= x <= 0.9, Mn ions reveal magnetic cluster glass properties. Except for x = 0.9, which exhibits degenerate semiconductive behavior, the temperature dependence of resistance shows insulating behavior for all other GCMO concentrations. This can be associated with the small average ionic radius of rare earth cations and colossal magnetoresistance (CMR) is observed for GCMO with x = 0.8 and x = 0.9 when the applied magnetic field exceeds 9 T. (C) 2017 Elsevier B.V. All rights reserved.
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