Thermopower and magnetocaloric properties in NdSrMnO/CrO3 composites

Abstract

The thermoelectric power (TEP) and magnetocaloric effect (MCE) for (Nd 0.6 Sr 0.4 MnO 3 ) 1-x /(CrO 3 ) x composites have been measured. The TEP measurements show a negative sign value of the Seebeck coefficient (S), in microvolts. TEP data construe in the low range of temperature by the magnon and phonon drag model, whereas at high temperature by small polaron conduction mechanism. Magnetic measurements exhibit that all composites show a paramagnetic-ferromagnetic transition with decreasing temperature. The Arrott plots of composites reveal the occurrence of a second order phase transition. The maximum value of magnetic entropy change (DS) is 2.37 J kg À1 K À1 , achieved fore the composite with x = 0.015. Moreover, the maximum value of relative cooling power (RCP) is 122.1 J kg À1 , achieved for the composite with x = 0.020. These composites may be appropriate for magnetic application near room temperature.

The Physical Properties of Submicron and Nano-Grained La0.7Sr0.3MnO3 and Nd0.7Sr0.3MnO3 Synthesised by Sol–Gel and Solid-State Reaction Methods

“…The hole-doped perovskite manganites with the general formula of RE 1−x A x MnO 3 , where RE is a rare earth ion (RE = La, Nd, Pr) and A is a divalent alkaline earth metal ion (B = Ba, Sr, Ca), have been investigated extensively due to the correlation between spin, charge, orbital, and lattice degrees of freedom [1][2][3]. Besides CMR, doped manganites have been discovered with some other intriguing properties, such as ferromagnetic-paramagnetic transition, metal-insulator transition, magnetocaloric effect (MCE), and charge order state [4][5][6][7][8]. A double exchange (DE) mechanism between pairs of Mn 3+ and Mn 4+ has been proposed to understand the interactions of charge and spin in manganites [9].…”

Enhancement of Optical, Electrical, Magnetic, and Thermopower Properties of LaMnO3 by Potassium‐Doping

“…A homemade apparatus described in our earlier study was used to measure the thermoelectric power. [ 48,49 ] A double‐beam UV–vis–NIR spectrophotometer (Model: JASCO, V‐570 in a range of wavelength from 200 to 2500 nm) was utilized to study the reflection properties of our samples. By using the Barrington instruments MS2/MS3 susceptibility system described in our earlier study, [ 50,51 ] the AC susceptibility of the compounds was examined over the temperature range of 100–400 K in a 250 T magnetic field with a frequency of 0.3 kHz.…”

The Interplay Between Heat Treatment and The Optical and Dielectric Properties of Nd0.7Ca0.3MnO3

“…Perovskite materials display a variety of fascinating characteristics, both in terms of theory and practical applications. Due to the enormous applications of these materials, many researches dealt with a detailed study of the properties of these materials [1][2][3][4][5][6].…”