Tunable spin reorientation transition and magnetocaloric effect in Sm0.7−xLaxSr0.3MnO3 series

Abstract

We report electrical resistivity, magnetic and magnetocaloric properties in Sm 0.7-

Magnetocaloric effect in (La1−Sm )0.67Pb0.33MnO3 (0 ≤ x ≤ 0.3) manganites near room temperature

“…Table 2. These values are larger than those reported for Pb or Sm substituted perovskite materials [26,37,40].…”

Structural distortion effect on the magnetization and magnetocaloric effect in Pr modified La0.65Sr0.35MnO3 manganite

“…Therefore, the variation in T C is attributed to the decrease of the Mn-O-Mn bond angles in the doped samples. In fact other recent studies of A-site doped maganites [10,25,29] also reveal that the ''mismatch effect factor'' of A-site cations influences the T C . In addition, from al [27].…”

“…This variation of <r A > is due to the fact that, when ions with smaller ionic radius are introduced at the A-site, a void between MnO 6 octahedra is created. This void results in an effective chemical pressure that is accommodated by rotating the octahedra and lowering the symmetry of the unit cell, thus, lengthening the Mn-O bonds and reducing the Mn-O-Mn bond angles from the ideal 180° [10,25]. As a consequence, the transfer interaction of e g electrons should be reduced.…”

“…There are many effects reported in the literature that cause considerably different magnetocaloric properties [21][22][23][24][25]. Therefore, it is very important to understand the relation between the structural distortion, magnetization and magnetocaloric properties, and the underlying physical mechanism of these doped perovskite manganites.…”

Tuning of normal and inverse magnetocaloric effect in Sm0.35Pr0.15Sr0.5MnO3 phase separated manganites

“…However, high cost, large thermal hysteresis and mechanical instability due to cracks developed in these materials having first order magnetic phase transition (FOMPT) pose certain challenges that should be overcome before these materials can find applications. A good magnetocaloric material is characterized by the three important quantities [6] (a) Magnetic entropy change (b) Adiabatic temperature change and (c) Refrigerant capacity. Generally, RC defines the amount of heat transfer between the cold and hot sinks in an ideal refrigeration cycle.…”