Bi–Mn Binary Phase Diagram in High Magnetic Fields

Abstract

To examine magnetic field effects on the BiMn equilibrium phase, a high-magnetic fields differential thermal analysis (HF-DTA) was performed for fields up to 18 T and temperatures ranging from 300 to 753 K. For zero field, the peritectic temperatures T p1 (BiMn 1.08 + Bi-rich liquid ¼ BiMn) and T p2 (¡Mn + Bi-rich liquid ¼ BiMn 1.08 ), and the eutectic temperature T E (the Bi-rich liquid ¼ Bi solid + BiMn) were determined to be 632, 721 and 538 K, respectively. The BiMn phase diagram at 18 T was obtained, which showed that T p1 increases with increasing magnetic fields at the rate of 2 K T ¹1. Furthermore, the liquidus boundary temperature T liq between BiMn 1.08 + liquid and Bi-rich liquid was found to increase nonlinearly with increasing magnetic field.

Enhancement of the Phase Formation Rate during In-Field Solid-Phase Reactive Sintering of Mn-Bi

“…After that, the heat treatments were carried out at 523 K for 3 h and 12 h with or without magnetic eld of 10 T. The annealing temperature was chosen as just lower than eutectic temperature of Mn and Bi. Herein, it is noted that the eutectic temperature of Mn and Bi was not in uenced by magnetic elds 11) . That is, this reactive sintering was Mn (solid) + Bi (solid) → MnBi (solid).…”

Fe-Fe3C binary phase diagram in high magnetic fields

“…Recently, high-field DTA (HF-DTA) equipment for fields up to 45 T has been developed by Mitsui et al [25]. The MFE in synthesis processes and phase equilibria has been studied for high-T C superconductors [26,27], and ferromagnetic MnBi [28][29][30] employing HF-DTA. In particular the Bi-Mn phase diagram in high magnetic field was obtained [30].…”

Preparation and Magnetic Properties of MnBi Alloy and its Hybridization with NdFeB

“…According to the phase diagram of Mn y Bi (100-y) system [12], MnBi phase was formed via a low temperature peritectic reaction process during the solidification process. The XRD patterns of the powders ground from MnBi arc-melted and annealed alloys are shown in Fig.…”

“…The phase responsible for the ferromagnetism of MnBi is formed only at temperature < 613 K [12] and is called as the lowtemperature phase (LTP). The complexity of the phase diagram of Mn-Bi system leads to the multiphase segregation of MnBi, Bi, and Mn in MnBi alloys.…”

“…Attempts for preparing high-performance single-phase MnBi alloys and bulk magnets have been intensively carried out during the last years [3,[6][7][8][9][10][11][12][13][14][15]. The phase responsible for the ferromagnetism of MnBi is formed only at temperature < 613 K [12] and is called as the lowtemperature phase (LTP).…”