We report the structural, morphological and magnetic properties of the Ni70Mn30 alloy prepared by Planetary Ball Mill method. Keeping the milling time constant for 30 h, the effect of different ball milling speeds on the synthesis and magnetic properties of the samples was thoroughly investigated. A remarkable variation in the morphology and average particle size was observed with the increase in milling speed. For the samples ball milled at 200 and 300 rpm, the average particle size and hence magnetization were decreased due to the increased lattice strain, distortion and surface effects which became prominent due to the increase in the thickness of the outer magnetically dead layer. For the samples ball milled at 400, 500 and 600 rpm however, the average particle size and hence magnetization were increased. This increased magnetization was attributed to the reduced surface area to volume ratio that ultimately led to the enhanced ferromagnetic interactions. The maximum saturation magnetization (75 emu/g at 1 T applied field) observed for the sample ball milled at 600 rpm and the low value of coercivity makes this material useful as soft magnetic material.

Abstract
 1. Introduction
 2. Experimental Procedure
 3. Results and Discussion
 4. Conclusions
 References

• Imad Hussain(School of Materials Science and Engineering, Changwon National University)
• Ji Eun Lee(School of Materials Science and Engineering, Changwon National University)
• So Eun Jeon(School of Materials Science and Engineering, Changwon National University)
• Hyun Ji Cho(School of Materials Science and Engineering, Changwon National University)
• Seok-Hwan Huh(School of Mechatronics Conversion Engineering, Changwon National University)
• Bon Heun Koo(School of Materials Science and Engineering, Changwon National University)
• Chan Gyu Lee(School of Materials Science and Engineering, Changwon National University) Corresponding author