Effect of Fe doping on magnetic properties and magnetoresistance in La1.2Sr1.8Mn2O7

Abstract

We report the effect of Fe doping on magnetic properties and magnetoresistance (MR) in the layered perovskite La1.2Sr1.8Mn2O7. Fe doping results in the weakening of ferromagnetic (FM) ordering, and the occurrence of a low-temperature spin-glass state in La1.2Sr1.8Mn2−xFexO7. Resistivity increases sharply with increasing Fe concentration. The metal–insulator transition disappears at a very low doping level (x=0.01), but the low-temperature MR effect is enhanced. These effects result from the replacement of Mn3+ by the doped Fe ions, which interrupts the path of double–exchange interaction and destroys the FM metallic state. Due to the anisotropic interaction in the layered perovskite, the magnetic properties and MR effect are more sensitive to Fe doping than those in ABO3-type perovskites.

Effect of Cr doping in the bilayer manganite La1.4Sr1.6Mn2O7

“…Some such studies have been undertaken during the past few years [7][8][9][10][11][12][13]. Cr is a very interesting substitution ion for Mn site, because Cr 3 + has the same electronic configuration (t 3 2g e 0 g ) as that of Mn 4 + , and closely identical ionic radius as that of Mn 3 + .…”

Re-entrant spin glass transition in La 0.96 − y Nd y K 0.04 MnO 3 : Origin and effects on the colossal magnetoresistivity

“…Indications of such a transition have already been reported for CMR compounds, but without presenting convincing experimental evidences for its existence. Usually, the authors consider that a low temperature cusp in the zero-field-cooled (ZFC) magnetisation, leading to a difference between the ZFC and field cooled (FC) magnetisation curves at low temperatures, is enough to evidence a low temperature RSG phase [6][7][8][9]. Ac-susceptibility measurements are sometimes added; a frequency dependent ac-susceptibility is then attributed to the RSG phase [10][11][12].…”

Synthesis and Characterization of Intergrowth Type Perovskite Oxide NdSr2MnCrO7

“…Only Ru-doped systems show enhanced FM and metallicity while the rest of the dopants destroyed the FM. [13][14][15][16][17][18][19][20] So it was thought interesting to synthesize a phase containing rare earth ion other than lanthanum and doped at Mn site and study its electrical and magnetic properties. The reasons to synthesise such a phase could be (i) the substitution at site B leads to tremendous variation in physical properties in many RP-phases and (ii) there are far fewer studies reported in the literature on RP-type (n = 2) manganites containing rare earth other than lanthanum.…”