Metastable Co3C nanocrystalline powder produced via reactive ball milling: Synthesis and magnetic properties

JOURNAL OF ALLOYS AND COMPOUNDS

卷:676

Article

Turgut, Z.¹  Lucas, M. S.¹  Leontsev, S.^1,2  Semiatin, S. L.¹  Horwath, J.¹ 

[1] Air Force Res Lab, Wright Patterson AFB, OH 45433 USA

[2] Univ Dayton, Res Inst, Dayton, OH 45469 USA

关键词: Hard magnets;    Mechanical alloying;    Coercivity;    Nanocrystalline alloys;    Metastable phases;   

DOI  :  10.1016/j.jallcom.2016.03.095

来源: Elsevier

【 摘 要 】

This study investigates reactive ball milling synthesis of a single phase metastable Co3C compound from starting mixtures of cobalt and graphite powders under argon and nitrogen environments. It reports their phase formations, magnetic, and structural properties. Regardless of the starting powder composition (25.0 or 33.3 at.% C) and milling atmosphere, reactive ball milling leads to the formation of the Co3C compound with an orthorhombic structure. Coercivities of the starting mixtures first increases with milling time as the Co3C compound starts to form and subsequently decreases due to structural defects induced by further milling. Higher graphite containing starting powder mixtures yield higher peak coercivity values and higher transformation rates. The formed Co3C compound exhibits a Curie temperature of 563 K and a decomposition temperature around 710 K. Compared to argon milled powders, reactive milling under a nitrogen atmosphere increases the coercivity and decomposition temperature of the Co3C compound. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

Free