Structural and magnetic properties of La _0.7 Sr _0.1 Ag _x MnO _3−δ perovskite manganites

Abstract

Ag-doped manganite powder samples, La0.7Sr0.1AgxMnO3−δ (x = 0.00, 0.025, 0.05, 0.075, and 0.10) were synthesized using the sol–gel method. X-ray diffraction patterns indicated that the samples had two phases with the perovskite being the dominant phase and Mn3O4 being the second phase. X-ray energy dispersive spectra indicated that the ratio of Ag to La was very close to that of the nominal composition in the samples. The specific saturation magnetizations at 300 K increased from 32.0 A·m2/kg when x = 0.00 to 46.8 A·m2/kg when x = 0.10. The Curie temperature, TC, of the samples increased from 310 K when x = 0.00 to 328 K when x = 0.10. Because the atomic concentration ratios of La, Sr, and Mn in the five samples were all the same and only the Ag concentration changed, the variations of the specific saturation magnetizations at 300 K and the Curie temperatures suggested that the Ag cations have been doped into the A sites of the perovskite phase in the samples.

Effects of Ni doping on the structural properties and collapse of magnetic ordering in NdFe 1− x Ni x O 3 (0.1 ≤ x ≤ 0.7) orthoferri

“…where Z is the number of formula units in one unit cell and 028101-4 its value is 4 for GdFeO 3 -type structures, M is atomic mass in gram, here the deviation from any stoichiometry is not taken into account in calculating M, N is Avogadro's number, and V is volume in unit cm 3 . Porosity of each sample is calculated from the values of theoretical density (d th ) and bulk density (d).…”

“…Owing to these properties oxide-based ceramics are widely used in numerous areas. [1][2][3] RFe 1−x B x O 3 orthoferrites (where R denotes a rare earth ion and B a transition metal ion such as Ni, Co, Mn, Cr) are one of the most studied classes of perovskites. Doping at B-sites affects the physical properties with change in their ionic radii, oxidation states and spin states which play a key role in determining the structural, electronic and magnetic properties.…”

“…Doping at B-sites affects the physical properties with change in their ionic radii, oxidation states and spin states which play a key role in determining the structural, electronic and magnetic properties. [3][4][5][6] The structure of NdFeO 3 is orthorombically distorted derivative of cubic perovskites with Pbnm symmetry. The crystallographic unit cell of NdFe 1−x Ni x FeO 3 can be visualized as three-dimensional (3D) tilted, slightly deformed and corner sharing FeO 6 octahedron while the A-site cations (Nd 3+ ) are dodecahedrally coordinated by 12 O 2− ions and fit in the cavities comprised of eight FeO 6 /NiO 6 octahedra.…”

Spin-dependent and spin-independent channels of electrical transport in perovskite manganites

“…The polycrystalline perovskites examined in this study, La 0.60 -Sr 0.40 Fe x Mn 1Àx O 3 (0 # x # 0.3), were prepared using the sol-gel method: 42,43 (i) stoichiometric amounts of La 2 O 3 (purity: 99.99%, red in air at 1073 K for 3 h before it was used), Sr(NO 3 ) 2 (purity: 99.5%) powder, and a Mn(NO 3 ) 2 solution (purity: 50%) were dissolved in a dilute HNO 3 solution at 343 K. Citric acid and ethylene glycol were added to the mixed solution as complexing agents until a completely homogeneous transparent solution was obtained. The molar ratio of citric acid (or ethylene glycol) to the perovskite molecule was 6 : 1.…”

Study of magnetic ordering in the perovskite manganites Pr0.6Sr0.4CrxMn1-xO3

“…[46][47][48][49][50] 2 were dissolved in dilute HNO 3 solution, and suitable amounts of citric acid and ethylene glycol were added as complexing agents until a completely homogeneous transparent solution was obtained. This solution was subjected to slow evaporation at 363 K in a water bath until a highly viscous residue was formed.…”