The influence of disorder on magnetocaloric effect and the order of transition in ferromagnetic manganite (La1−x Nd x )2/3(Ca1−y Sr y )1/3MnO3

Abstract

Magnetocaloric effect and order of transition in (La 1-x Nd x ) 2/3 (Ca 1-y Sr y ) 1/3 MnO 3 , prepared by conventional solid-state reaction, have been investigated. Using Banerjee criterion, we demonstrate first-order transition for (J1) and (J2) as well as second-order transition for (J3), (J4), and (J5) samples. The DS M max is ranging between 9.18 Jkg -1 K -1 and 4.87 when Nd and Sr content changes leading to relative cooling power (RCP) varying between 330 and 229.35 J/kg. Both DS M max and the RCP are found sensitive to the disorder r 2 . The universal behavior obtained from DS variation curves confirmed the first-order transition for (J1) and (J2) samples and second-order transition for (J3), (J4), and (J5) samples obtained by Banerjee criterion. All samples with second-order phase transition exhibit inhomogeneous character estimated from local exponent n.

Theoretical Insights into the Stability of Perovskite Clusters by Studying Magnetization and Magnetocaloric Effect of Nd0.6Sr0.4MnO3 Compound at Room Temperature

“…The relative cooling power is the negative of the product of the maximum magnetic entropy change, and the full-width at half-maxima ( T FWHM ) can be carried out using Eq. 5 [34,35]: Another very important parameter for magnetic refrigeration is the relative cooling power (RCP) pointing to the transferred heat between the cold and the hot reservoirs in a refrigerator during one ideal thermodynamic cycle [36][37][38], and it is defined as:…”

“…where a is a constant and the n exponent depends on the magnetic state of the sample. It can be locally calculated as follows [43,44]:…”

Design of Dual Purpose Fe‐metallogel for Magnetic Refrigeration and Fabrication of Schottky Barrier Diode

“…[29][30][31][32][33] Taking cue from this, we envisioned that the cryogenic magnetic cooling behaviour of a Fe 3 + based metallogel with least periodic microstructure perfectly suit the purpose. [34][35][36][37][38] It is noteworthy here that Fe 3 + ion with characteristic 6 S 5/2 ground state term (S = 5/2, L = 0) fulfils two basic prerequisites for effective MCE, viz. (a) high spin: facilitating the largest entropy per metal centre, equals to a value of R ln(2S + 1), and (b) zero orbital momentum.…”

“…The extent of MCE depends on three major metal‐specific features: (i) large spin ground state, (ii) the zero orbital momentum and (c) the weak super‐exchange interactions [29–33] . Taking cue from this, we envisioned that the cryogenic magnetic cooling behaviour of a Fe 3+ based metallogel with least periodic microstructure perfectly suit the purpose [34–38] . It is noteworthy here that Fe 3+ ion with characteristic 6 S 5/2 ground state term (S=5/2, L=0) fulfils two basic prerequisites for effective MCE, viz.…”