First order paramagnetic–ferromagnetic phase transition in Tb3+ doped La0.5Ca0.5MnO3 manganite
| Autor: | P. Chaddah, R.R. Doshi, P. S. R. Krishna, Uma Khachar, A. Banerjee, D. G. Kuberkar, P.S. Solanki |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Phase transition
Materials science Condensed matter physics Condensed Matter Physics Manganite Electronic Optical and Magnetic Materials Magnetization Paramagnetism Ferromagnetism Critical point (thermodynamics) Electrical resistivity and conductivity Condensed Matter::Strongly Correlated Electrons Electrical and Electronic Engineering Ground state |
| Zdroj: | Physica B: Condensed Matter. 406:4031-4034 |
| ISSN: | 0921-4526 |
| DOI: | 10.1016/j.physb.2011.07.028 |
| Popis: | Effect of A-site disorder in half-doped La 0.5 Ca 0.5 MnO 3 created by the substitution of Tb at La site is studied through temperature dependent neutron diffraction, resistivity, and magnetization on La 0.375 Tb 0.125 Ca 0.5 MnO 3 (LTC) to identify the evolution of phases as a function of temperature and magnetic field. Contrary to the parent system, the paramagnetic (PM) to ferromagnetic (FM) transition is found to be of first order but becomes observable only in fields above 1 T. Absence of this transition in zero and low fields along with the observation of a very intriguing and irreversible M – H curve at low temperature raises the question about the ground state of the system. It is identified from the specially designed measurement protocol that the ground state of the system becomes FM, contrary to the parent LCMO. However, this remains masked because of the hindrance to the transformation kinetics of the PM–FM first order transition in low fields. Significantly, though the thermal hysteresis of the first-order transition decreases with the measurement field, collapse of such a behavior to a critical point is not observed in LTC, unlike earlier observations in some other manganites. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect