Formation of strong L10-FePd/α-Fe nanocomposite magnets by visualizing efficient exchange coupling. Issue 7 (28th May 2019)

• Record Type: Journal Article
• Authors: Matsumoto, Kenshi; Sato, Ryota; Trinh, Thang Thuy; Sakuma, Noritsugu; Shoji, Tetsuya; Haruta, Mitsutaka; Kurata, Hiroki; Teranishi, Toshiharu
• Is Part Of: Nanoscale advances. Volume 1:Issue 7(2019)
• Page Start: 2598
• Page End: 2605
• Publication Date: 2019-05-28
• Subjects: 620.5
• DOI: 10.1039/c9na00225a
• Languages: English
• ISSNs: 2516-0230

Abstract

Abstract : FORC analysis distinguished a microscopically undetectable difference in phase-segregation structure in nanocomposite magnets, finding both efficient and inefficient exchange coupling. Abstract : Conceptual nanocomposite magnets (NCMs) composed of exchange-coupled hard/soft magnetic phases have been expected to show excellent magnetic performance based on simultaneous high coercivity ( H c ) and high saturation magnetization ( M s ). In our previous works, however, the H c was considerably lower than its theoretical value ( H a ), which prevented us from improving the performance of NCMs. Here, we show that the H c of isolated particulate L 10 -FePd/α-Fe NCMs is dominated by their phase segregation into core/shell-like structures versus Janus-like structures. Using first-order reversal curve (FORC) analysis, we clearly distinguished a microscopically undetectable difference in the phase-segregation structure in the NCMs, finding both efficient and inefficient exchange coupling. The nanostructurally controlled NCMs dominated by core/shell-like structure with efficient exchange coupling showed the largest energy product (( BH )max = 17.5 MGOe) in the Fe–Pd system and the highest H c / H a value (26.5%) among all NCM powders.