Physical properties of 20% Cr-doped Pr0.7Ca0.3MnO3 perovskite

Possibility of controlling the conduction mechanism by choosing a specific doping element in a praseodymium manganite system

“…It has been reported that the manganite system Pr 0.7 Ca 0.3 MnO 3 is a good candidate for theoretical analyses and experimental investigations. [21][22][23][24][25][26][27][28][29][30] The interesting physical properties of such an oxide family are based principally on the mixed valence character (Mn 3+ , Mn 4+ ) of Pr 0.7 Ca 0.3 MnO 3 manganite. This character is imposed by the coexistence of a trivalent praseodymium ion (70% of Pr 3+ ) and a bivalent alkaline earth metal ion (30% of Ca 2+ ) in the A-site.…”

“…Previous studies have veried that the Pr 0.7 Ca 0.3 MnO 3 system exhibits ferromagnetic metallic behavior. [22][23][24][25][26][27][28][29][30] In this context, the substitution by transition metal elements modies the mixed valence leading to strengthen the interactions between the double and the superexchange mechanisms. It had shown that the substitution of the manganese affects mainly the Mn 3+ /Mn 4+ ratio, leads to modify the relative cooling power (RCP), the magnetoresistance effects and the transport properties of manganites.…”

“…For the case of Ni-PCMO and Cr-PCMO compounds, the activation energies E a ¼ 80 meV and E a ¼ 97 meV were obtained respectively. According to our previous work in ref 22,. we found that the activation energy of the parent compound (Pr 0.7 Ca 0.3 MnO 3 ) is E a ¼ 26 meV.…”

Structural, magnetic, electrical and dielectric properties of Pr0.8Na0.2MnO3 manganite

“…The physical properties of maganites oxides can be improved by closing dopants, 7,8 substitution sites 9 preparation route 10,11 and insertion of nanostructures. 12 Many methods of synthesis have been used to manufacture rare earth manganites with perovskites structure, including solid-state reaction, 13,14 sol-gel, 15 coprecipitation, 16 combustion, 17 hydrothermal, 18 acrylamide polymerization 19 and microwave techniques. 20 Most of the work available on the preparation of sodium doped praseodymium manganites is commonly based on high temperature ceramic method.…”

Magnetocaloric effect and its implementation in critical behaviour study of La0.67Ca0.33Mn0.9Fe0.1O3

“…Several compounds with a high MCE can be elaborated at different (low, intermediate and high) temperatures, and the major problem remains to get the samples with a high MCE at a low external magnetic field, which is advantageous for application as magnetic cooling, working in the fields produced by permanent magnets [13]. Manganites are promising candidate materials to satisfy this requirement and might be of the option of future magnetic cooling [14][15][16]. These perovskites (rafik_mnassri@yahoo.fr) are characterized by the strong competition among a ferromagnetic double-exchange (DE) interaction, an antiferromagnetic super-exchange interaction and the spin-phonon coupling [17][18][19].…”