Synthesis of Nd2Fe14C compound by high-energy ball-milling Nd–Fe alloy in heptane and annealing under vacuum. (3rd May 2016)

• Record Type: Journal Article
• Authors: Geng, H M; Ji, Y; Feng, X Y; Zhang, J J; Ran, Z; Yan, Y; Wang, W Q; Su, F; Du, X B
• Is Part Of: Journal of physics. Volume 49:Number 21(2016)
• Publication Date: 2016-05-03
• Subjects: Nd2Fe14C -- high-energy ball-milling -- heptane -- disproportionation -- permanent magnetic properties; Physics -- Periodicals; 530
• DOI: 10.1088/0022-3727/49/21/215001
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: A simple synthesis route for the Nd2 Fe14 C compound with good permanent magnetic properties is presented. Being high-energy ball-milled in heptane (C7 H16 ) for 8 h, the NdFe3.5 alloy consisting of Nd2 Fe17 and Nd phases disproportionates into NdH2+ δ and α -Fe. Subsequently, NdH2+ δ decomposes when annealed from room temperature to 900 °C under vacuum, and H2 is released. Meanwhile Nd2 Fe14 C, NdC and little α -Fe phases are formed in the final product. H and C atoms come from the decomposition of heptane. Coercivity of 1.39 T and maximum magnetic energy product of 62.7 kJ m −3 have been achieved. Too short a ball-milling time results in the insufficient disproportionation of NdFe3.5 alloy and the residue of Nd2 Fe17 phase in the final product. Too long a ball-milling time results in the appearance of NdC2 and more α -Fe phases besides Nd2 Fe14 C and NdC phases. Hexane (C6 H14 ), octane (C8 H18 ) and nonane (C9 H20 ) have been proved to have a similar effect to heptane.