tailieunhanh - Extraordinary magnetic properties of LaFeO3 system doped Ti, Co, Cu

LaFeO3 system with doped Ti, Co, Cu was manufactured by solid state reaction method, it was sintered at 12500C and 12900C in 10 hours with a heating rate of 3 0C/min. Using X-ray diffraction and Scanning Electron Microscope (SEM) to examine the structure, it reveals that samples are single-phase and orthogonal-perovskite structure describing by the Pnma space group, the unit cell volume of the samples increases when Ti, Co, Cu are doped to replace ion Fe+3. | EXTRAORDINARY MAGNETIC PROPERTIES OF LaFeO3 SYSTEM DOPED Ti, Co, Cu NGUYEN THI THUY - TRAN DUY THANH CAO THỊ THUY LINH - HOANG HUONG QUYNH Physics Department, Hue University of Education, Hue University Email: nguyenthithuy0206@ Abstract: LaFeO3 system with doped Ti, Co, Cu was manufactured by solid state reaction method, it was sintered at 12500C and 12900C in 10 hours with a heating rate of 30C/min. Using X-ray diffraction and Scanning Electron Microscope (SEM) to examine the structure, it reveals that samples are single-phase and orthogonal-perovskite structure describing by the Pnma space group, the unit cell volume of the samples increases when Ti, Co, Cu are doped to replace ion Fe+3. The size of particle increase while raising the temperature of sintering. Doping Ti, Co, Cu ions has strongly changed the magnetic properties of the sample system. Magnetic hysteresis loops M(H) and magnetocaloric M(T) of the samples are measured in different magnetic fields and show interesting results. All the samples shown strong ferromagnetism, among which La()O3 shown the strongest and its Curie temperature is about 4500C. Keywords: LaFeO3 doped Ti, Co, Cu; magnetic hysteresis loop M(H); magnetocaloric loop M(T); strong ferromagnetism 1. INTRODUCTION Perovskite material has the general form ABO3 with A is the cation of rare earth element or alkaline earth metals (Y, La, Nd, Sm, Ca, Ba), B is the cation of transition metal (Mn, Co, Fe). The replacement of different elements into position of A or B or simultaneously replacing two positions can create lots of change in nature. When there is a doping, the electric property of perovskite materials has a lot of promising improvements to suit different application purposes. Studies on the manufacture and investigating perovskite materials have been made with familiar families of materials such as SrTiO3, LaMnO3, CaMnO3, LaFeO3 [1-8]. When part of the ion of Ln (rare earth element), Mn or Co is .