Structural and magnetic properties with large reversible magnetocaloric effect in (La sub(1-x)Pr sub(x)) sub( 0.85)Ag sub(0.15)MnO sub(3) (0.0 less than or equal to x less than or equal to 0.5) compounds

• Published in: Philosophical magazine (Abingdon, England) England), 2016-04, Vol.96 (10), p.922-937
• Main Authors: Ayas, Ali Osman, Akyol, Mustafa, Ekicibil, Ahmet
• Format: Article
• Language: English
• Subjects: Cooling; Diffraction; Doping; Entropy; Ferromagnetism; Magnetic properties; Scanning electron microscopy
• ISSN: 1478-6435; 1478-6443
• DOI: 10.1080/14786435.2016.1144939

We report on the effect of Pr doping on structural, magnetic and magnetocaloric properties in (La sub(1-x)Pr sub(x)) sub(0.85)Ag sub(0.15)MnO sub(3) (0.0 less than or equal to x less than or equal to 0.5) compounds. The main crystal structure has been studied by performing X-ray diffraction method and structural analysis based on Rietveld method where it is found that although samples at low concentration level (x less than or equal to 0.2) have rhombohedral phase [Image omitted.], others (x greater than or equal to 0.3) have orthorhombic (Pbnm) phase. Scanning electron microscope images show that the average particle size decreases by increasing Pr amount in the main structure. It is observed that the second-order transition temperature from ferromagnetic to paramagnetic phase is dramatically decreased from 262 to 138 K by increasing Pr concentration in (La sub(1-x)Pr sub(x)) sub(0.85)Ag sub(0.15)MnO sub(3). On the other hand, all samples have also antiferromagnetic coupling observed below T sub(N) ~ 50 K. The maximum magnetic entropy change (- Delta S sub(M)) sub(max) and relative cooling power values were found in the range of 7.90-2.88 J/kg K and 213.32-153.50 J/kg, respectively, under 50 kOe field change in our samples. It can be argued that particularly the compounds LPAM with x = 0.0, 0.1 and 0.2 are expected to be promising candidate for magnetic refrigeration.