Structural distortion driven polaronic transport and table-like magnetocaloric properties in polycrystalline
Kalipada Das1, Dipak Mazumdar2, I Das3
1Department of Physics, Seth Anandram Jaipuria College, 10 Raja Naba Krishna Street, Kolkata-700005, West Bengal, India.
Abstract:
This research mainly explores the structural, magnetic, magneto-transport, and magnetocaloric properties of the polycrystalline Tb0.7Sr0.3MnO3 compound. The results reveal a significant modification of the compound's ground state with increasing the strength of the magnetic field. The strong distortion in the crystal structure highly controls the magnetic and magneto-transport properties of the system. Along with this, a prominent 'table-like' nature in the temperature-dependent magnetic entropy change has been noticed, showcasing the potential application of the compound in the field of Ericsson refrigeration technology. Notably, a substantial low-field magnetoresistance is noticed around T ∼ 60 K. The temperature dependent electrical resistivity data can be well explained with the help of polaronic transport conduction mechanisms namely small-polaron hopping and variable-range hopping models. Various significant parameters are calculated and the system possesses a non-adiabatic polaron hopping mechanism with a large electron-phonon coupling constant. This investigation contributes valuable insights into the intricate dynamics of the 3d-4f exchange interaction and crystallographic distortion, shedding light on the underlying mechanisms governing the magnetic and electrical transport properties of the Sr-doped TbMnO3 compound.
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