Title :
Electron Transport Properties of Fe-Doped Bi-Layered Managnites La1.6Dy0.2Sr1.2Mn2-xFexO7
Author :
Basith, M.A. ; Shaha, T. Chanda ; Huq, M.
Author_Institution :
Dept. of Phys., Bangladesh Univ. of Eng. & Technol., Dhaka
Abstract :
The effect of Fe on the electron transport and magnetoresistive properties of layered perovskite manganites La1.6Dy0.2 Sr1.2Mn2 - xFexO7, which consists of two [MnO2] layers intertwined with a rock-salt type layer of [(La,Dy,Sr)2O2] have been investigated. The metal-insulator (M-I) transition and magnetoresistance phenomena were observed. The substitution of Mn by Fe decreases M-I transition temperature. As the ionic radii of Mn3+ and Fe3+ are similar for low Fe content samples, the crystal distortion induced by Fe substitution is not obvious. But the substitution of Mn by Fe suppresses the double-exchange interaction, weakness the ferromagnetism and consequently decreases the M-I transition temperature. The substitution of Fe also causes a depletion of the Mn3+/Mn4+ ratio and the population of the hopping electrons that ultimately reduces metallic conduction. The polycrystalline samples exhibit a sharp drop in the magnetoresistance at low magnetic fields
Keywords :
chemical exchanges; doping; dysprosium compounds; hopping conduction; iron; iron compounds; lanthanum compounds; magnetic multilayers; magnetoresistance; manganese compounds; metal-insulator transition; strontium compounds; LaDySrMnFeO; bi-layered manganites; crystal distortion; double-exchange interaction; electron transport properties; ferromagnetism; hopping electrons; ionic radii; layered perovskite manganites; magnetoresistance phenomena; magnetoresistive properties; metal-insulator transition; metallic conduction; substitution; transition temperature; Colossal magnetoresistance; Conductivity; Doping; Electrons; Iron; Magnetic fields; Magnetic materials; Magnetic properties; Powders; Temperature;
Conference_Titel :
Electrical and Computer Engineering, 2006. ICECE '06. International Conference on
Conference_Location :
Dhaka
Print_ISBN :
98432-3814-1
DOI :
10.1109/ICECE.2006.355652
