Neutron Diffraction, NMR and Magneto-Transport Properties in the Pr0.7Sr0.3MnO3 Perovskite Manganite

Abstract

Strontium substituted praseodymium manganite Pr 0.7 Sr 0.3 MnO 3 powder was synthesized by a solid state reaction method at 1400 C. Neutron diffraction analysis at room temperature and at 14.5 K shows that our sample belongs to the Pnma space group at both temperatures. At low temperature, the refinement gave 3.368m B for the Mn atoms and 0.273m B for the Pr atom, aligned ferromagnetically along the crystallographic y-axis. Magnetic measurements show that our sample exhibits a paramagnetic-ferromagnetic transition with decreasing temperature. The Curie temperature, T C , is found to be 250 K. Electrical studies show a semiconductor-metal transition at T r = 260 K. This transition temperature is observed in the vicinity of the Curie temperature T C . Magnetotransport properties show a sharp drop in resistivity as a function of the magnetic applied field. Our sample displays a magnetoresistance effect at 8 T of about 80% in the vicinity of the Curie temperature T C . 55 Mn NMR measurements at 4.2 K confirm the metallic behavior at low temperature. The time average resonance frequency indicates that electron hopping between Mn 3+ and Mn 4+ occurs over the whole crystal.

Bi doping effects on the physical properties of Pr0.6Sr0.4Mn1−xBixO3 (0≤x≤0.2) manganese oxides

“…6 pulverizing, the powders were pressed into pellets (of about 1 mm thickness) and sintered at 1400 • C in air for 3 days with intermediate regrinding and repelling. Finally, the pellets were rapidly quenched to room temperature in air.…”

“…The perovskite-type manganese oxides Ln 1−x A x MnO 3 (Ln is a trivalent rare-earth element and A is a divalent alkaline-earth or a monovalent alkali metal) have known a very big interest since the discovery of colossal magnetoresistance effects in such materials [1][2][3][4][5][6]. The substitution of the trivalent rare-earth element by a divalent or a monovalent one induces a mixed valence Mn 3+ and Mn 4+ ions.…”

“…These systems have been given much attention because they could possibly be used for sensor applications [12]. Several studies have been performed on the effects of the substitution in the A site [4,6,13,14], however only few studies have been reported on the substitution effects in the B site [15][16][17][18].…”

Granular and layered ferroelectric–ferromagnetic thin-film nanocomposites as promising materials with high magnetotransmission effect

“…The granular composites of a nano-particulated perovskite manganite Pr 0.7 Sr 0.3 MnO 3 (a ferromagnetics with T C 300 K [6]) inside the ferroelectric hexagonal manganite LuMnO 3 matrix were obtained via self-organization process owing to the immiscibility gap between the two phases. Hexagonal LuMnO 3 chosen as a ferroelectric constituent, can be easily grown epitaxially on the (111) ZrO 2 (Y 2 O 3 ) substrate due to an excellent coincidence of oxygen crystallographic positions at the interface between the two structures [7].…”

NMR study of magnetic properties of Pr1−xSrxMnO3 (0.2 ⩽ x ⩽ 0.5)

“…A coupling between Pr and Mn spins would cause a change in the hyperfine field at Mn. Pr magnetic moment has been observed to be 0.273 m B in Pr 0.7 Sr 0.3 MnO 3 [5]. The multi-peak spectrum has also been observed in Nd 1Àx Sr x MnO 3 [6].…”