Structure and phases of low-neodymium NdFeB permanent magnets

Abstract

Structures and phase compositions of two low-neodymium magnetically hard materials, differing by the way of preparation -centrifugal atomization and melt spinning -were compared using Mössbauer spectroscopy, X-ray diffraction and measurements of thermomagnetic curves. Better hard magnetic characteristics of the melt-spun material are explained on the basis of the differences in the content of surface and/or interface Fe(Nd,B) phases. Their remarkable presence in the centrifugally atomized material lowers the content of Fe3B, Fe2B, α-Fe, and Nd2Fe14B phases that are responsible for the magnetic quality of the material. There are only subtle differences in the phase compositions of both materials after thermomagnetic measurement, where the α-Fe phase prevails as a product of the thermal decomposition.

Production and Characterization of Nanostructured Powders of Nd2Fe14B and Fe90Al10 by Mechanical Alloying

“…Permanent magnets based on rare earth (RE) elements, such as Nd 2 Fe 14 B, play a fundamental role in current and emerging technologies; they are found in commonly used devices (computers, speakers, smartphones, etc. ), in the development of electric vehicles, and are an indispensable input for the construction of electrical generators capable of producing electrical energy from renewable natural sources such as water (hydroelectric power), wind (wind power) and the sea (wave energy) [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. For this reason, the design of high-performance permanent magnets represents a need at the industrial level [ 1 , 2 , 5 , 6 , 7 ].…”

“…), in the development of electric vehicles, and are an indispensable input for the construction of electrical generators capable of producing electrical energy from renewable natural sources such as water (hydroelectric power), wind (wind power) and the sea (wave energy) [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. For this reason, the design of high-performance permanent magnets represents a need at the industrial level [ 1 , 2 , 5 , 6 , 7 ]. Permanent magnets usually contain large amounts of RE and other elements that are difficult to supply, such as Pr, Sm, Dy, Tb, Nd and Co, most of which are mined in foreign countries such as China, Congo, Russia and the United States [ 1 , 2 , 3 , 4 ].…”