Structure, ferromagnetism and magnetotransport properties of nanopowders of Pr0.67Ca0.33FexMn1−xO3 manganites oxide prepared by sol–gel method

Structural, magnetic and magneto transport properties of Pr0.67Ca0.33FexMn1−xO3 with 0 ⩽ x ⩽ 0.3 nanopowder samples have been investigated. Powder samples have been elaborated by sol–gel method. Rietveld analysis of powder X-ray diffraction show that the samples crystallise in the orthorhombic perovskite system with Pnma space group. The average crystallite size of 50 nm was obtained by X-ray diffraction. The investigated samples exhibit a ferromagnetic to paramagnetic transition with increasing temperature. The presence of manganese in the structure leads to an increase of the Curie temperature as well as to spontaneous magnetization. Electrical investigations showed that all our samples exhibit a semi-conducting behavior at high temperature and a metallic-like one at low temperature. A large magnetoresistance has been observed in the samples studied. The magnetization versus applied magnetic field shows a small coercive field and an unsaturated magnetization which indicates that the nanoparticles of all samples are superparamagnetic at around room temperature.

► The magnetic characteristic and analysis have been done for Pr0.67Ca0.33FexMn1−xO3.
► The average particle size from 50 nm fabricated by sol–gel method.
► Magnetic measurements showed the ferromagnetic to paramagnetic transition.