Magnetic properties of mechanically alloyed Mn-Al-C powders

O. Kohmoto, N. Kageyama, Y. Kageyama, H. Haji, M. Uchida, Y. Matsushima

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)

Abstract

We have prepared supersaturated-solution Mn-Al-C alloy powders by mechanical alloying using a planetary high-energy mill. The starting materials were pure Mn, Al and C powers. The mechanically-alloyed powders were subjected to a two-step heating. Although starting particles are Al and Mn with additive C, the Al peak disappears with MA time. With increasing MA time, transition from α-Mn to β-Mn does not occur; the α-Mn structure maintains. At 100 h, a single phase of supersaturated-solution α-Mn is obtained. The lattice constant of α-Mn decreases with increasing MA time. From the Scherrer formula, the crystallite size at 500 h is obtained as 200, which does not mean amorphous state. By two-step heating, high magnetization (66 emu/g) was obtained from short-time-milled powders (t=10 h). The precursor of the as-milled powder is not a single phase α-Mn but contains small amount of fcc Al. After two-step heating, the powder changes to τ-phase. Although the saturation magnetization increases, the value is less than that by conventional bulk MnAl (88 emu/g). Meanwhile, long-time-milled powder of single α-Mn phase results in low magnetization (5.2 emu/g) after two-step heating.

Original languageEnglish
Article number012016
JournalJournal of Physics: Conference Series
Volume266
Issue number1
DOIs
Publication statusPublished - Jan 1 2011

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Magnetic properties of mechanically alloyed Mn-Al-C powders'. Together they form a unique fingerprint.

Cite this