Enhanced Magnetic Squareness in Manganese-Bismuth Mechanical Alloys Incorporating Magnesium Oxide

  • Thanida CHAROENSUK Walailak University Thasala District Nakhon si Thammarat
  • Chitnarong SIRISATHITKUL Walailak University Thasala District Nakhon si Thammarat
  • Upsorn BOONYANG Walailak University Thasala District Nakhon si Thammarat
  • Pongsakorn JANTARATANA Kasetsart University Bangkok
Keywords: manganese-bismuth, magnesium oxide, mechanical alloying, coercive field, magnetic squareness

Abstract

Manganese-bismuth (MnBi) mechanical alloys have been under development for novel permanent magnets without rare-earth elements. The ball-milling of bismuth (III) oxide and manganese powders in this work leads to soft magnetic MnBi alloys with rod-like MnO impurity and highly unbalanced compositions. Interestingly, the introduction of magnesium (Mg) as reducing element during the milling gives rise to unique magnetic properties. The obtained MnBi alloys incorporating plate-like MgO has an enhanced magnetic squareness but minimal coercive field. The magnetic squareness remains high after the heat treatment and washing. The washing in ammonia also brings about a balanced composition between Mn and Bi.
Published
2019-03-15
Section
METALS, ALLOYS, COATINGS