Than 1% of a second phase was present in our samples. Peaks were observed in the difference pattern, indicating that less R factor (Rf) and the goodness-of-fit indicator (v2). Refinement is evaluated through several parameters: the pattern Phase refinements of each coexisting phase. Rietveld refinement of the X-ray powder data was carried In the temperature range 70–300 K using a SQUID magnetometer. Temperature and magnetic applied field were performed on dense ceramic pellets Magnetization measurements versus temperature and applied magnetic field were recorded by vibrating sample and SQUID magnetometer. Using the Scherrer formula, and also from the SEM micrograph. The average particle size of the samples was estimated from X-ray peak width by X-ray diffraction at room temperature using a SIEMENS D500 diffractometer withĬuKa radiation source in the 2h scan range from 20° to 80° by the Rietveld analysis. Phase purity, homogeneity, and crystal properties were determined by powder The pellets were finally put in the furnace Promote contact at the grains boundaries. They are then placed in platinum crucibles and are compressed into pellets 12 mm in diameter and 2 mm thick in order to The powders elaborated are then placed in a mortar, are finely ground forġ0 min to obtain a homogeneous mixture. The gel was dried at 250 ☌ and calcinated at 500 ☌ for 6 h to get the desired Under constant stirring at 80 ☌ to eliminate the excess water and to obtain a viscous The solution was then heated on a thermal plate The precursors were dissolved in water and mixed with ethylene glycol and citric acid, forming a stable solution. Reaction by mixing precursors Pr2O3, MnO2, Fe2O3 and CaO up to 99.9% purity in theĭesired proportion according to the following reaction:Ġ:335 Pr2 O3 þ 0:33 CaO þ x=2 Fe2 O3 þ ð1 xÞ MnO2
Nanopowders of Pr0.67Ca0.33FexMn1xO3 have been elaborated using the sol–gel On Sabbatical leave from Yarmouk University, Jordan.Ġ925-8388/$ - see front matter Ó 2012 Elsevier B.V. Address: Faculté des Sciences de Sfax, B.P. Properties of Pr0.67Ca0.33FexMn1xO3 nanopowders elaborated by We report synthesis, structure, magnetic and magnetotransport Temperature and owing to their properties. (CMR) and behavior around Curie temperature (Tc) near room Manganites have been attracting the focus of materials researchersįor over more than a decade due to huge decrease in resistivity onĪpplication of magnetic field, called as colossal magnetoresistance Technological applications in magnetic ordering and sensors. Phenomena and properties exhibited, but also due to their potential Manganites are of vital interest to a wide community of materials scientists not only because of the fascinating WithĪdvances in information technology, more sensitive and high magnetoresistive materials are required for high speed electronic and Interesting electrical, magnetic and catalytic properties. Sr, Ba.) have attracted considerable attention because of their Rare earth (Ln = La, Pr, Sm.) and A is a divalent element (A = Ca, Perovskite-type complex manganite Ln1xAxMnO3 were Ln is a 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 magnetization versus applied magnetic A large magnetoresistance has been observed in the samples studied. Semi-conducting behavior at high temperature and a metallic-like one at low temperature. Electrical investigations showed that all our samples exhibit a The presence of manganese in the structure leads to an increase of the Curie temperature as The investigated samples exhibit a ferromagnetic to paramagnetic transition with increasing The average crystallite size of 50 nm was obtained by X-rayĭiffraction.
Rietveld analysis of powder X-ray diffraction show that the samples crystallise in the orthorhombic Powder samples have been elaborated by sol–gel method. Structural, magnetic and magneto transport properties of Pr0.67Ca0.33FexMn1xO3 with 0 6 x 6 0.3 nanopowder samples have been investigated. King Faisal University, Hofuf 31982, Saudi Arabia Sfax University, National School of Engineers, B.P.W 3038, Tunisia Sfax University, Faculty of Sciences, B.P. Of Pr0.67Ca0.33FexMn1xO3 manganites oxide prepared by sol–gel method Journal homepage: Structure, ferromagnetism and magnetotransport properties of nanopowders Journal of Alloys and Compounds 543 (2012) 152–158Ĭontents lists available at SciVerse ScienceDirect
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