Title of article :
Effect of Annealing Temperature and Composition on Magnetic Properties of Manganese-Bismuth Homogenized in Tube Furnace
Author/Authors :
Sirisathitkul ، Chitnarong Division of Physics - School of Science, Functional Materials and Nanotechnology Center of Excellence - Walailak University , Sukonrat ، Patchara Office of Scientific Instrument and Testing - Prince of Songkla University , Jantaratana ، Pongsakorn Department of Physics - Faculty of Science - Kasetsart University , Charoensuk ، Thanida Functional Materials and Nanotechnology Center of Excellence - Walailak University
Abstract :
Repeated heat treatment on manganese-bismuth (MnBi) in a tube furnace increases the homogeneity of rare-earth-free magnets. Ferromagnetic low temperature phase (LTP) MnBi is formed after heating Mn and Bi in a ratio of 2:1 at 1000 °C for 1 h and then 400 °C for 1 h. Areas with comparable compositions of Mn and Bi are detected, but some Mn and Bi remains segregate after using this stepped heating 3 times. The subsequent annealing at 340 °C gives rise to higher magnetizations and coercivity than those using 410 °C annealing. Increasing the starting Mn:Bi ratio to 4:1 reduces the coercivity and remanent magnetization due to the increase in Mn oxidation at the expense of ferromagnetic phase.
Keywords :
MnBi , Rare , earth , free magnet , Coercivity , Remanent magnetization , Tube furnace
Journal title :
Iranian Journal of Materials Science and Engineering
Journal title :
Iranian Journal of Materials Science and Engineering
