In situ TEM study of Nd-rich phase in NdFeB magnet
نویسندگان
چکیده
Hot stage in transmission electron microscope has been used to study the structure and stability of Nd-rich phase in NdFeB magnet. The present observation shows that the so-called complex cubic phase is in fact the prototype of Mn2O3 (space group Ia 3) with lattice parameter of a 1⁄4 1:08nm: The Nd-rich phase with P 3m1 structure (h-Nd2O3) was first observed to be transformed from the BCC phase after in situ heating over 400 1C. The orientation relationship between these two structures satisfies as follows: (0 0 0 1)HCP//(2 0 0)BCC, ð10 1 0ÞHCP==ð0 2 0ÞBCC; 1⁄2 1 2 1 0 HCP==1⁄20 0 1 BCC: It is argued that the h-Nd2O3 was arising from the oxidation of the BCC Nd-rich phase rather than from Nd2Fel4B matrix phase as suggested in the literature. r 2004 Elsevier B.V. All rights reserved. PACS: 75.50.Ww; 61.14.Lj; 68.37.Lp
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