Metastable and stable magnetic phases in as-cast and annealed Pr80Fe15(B1−xCx)5 alloys (0.0≤x≤1.0)

Microstructure and magnetic properties of Pr95−xFexC5 (15 ≤ x ≤ 65) alloys

“…Similar microstructure was observed by López et al in as-cast Nd 95−x Fe x C 5 alloys [7]. In comparison with the microstructure for as-cast Pr 80 Fe 15 C 5 alloys [2,6], the amount of needles for x = 25 is high. For x = 35 the optical micrograph (Fig.…”

“…For x = 25, only one magnetic transition is observed around 230 • C corresponding to the D 1 phase. According to the magnetic and microstructural analyses carried out in as-cast Pr 80 Fe 15 C 5 alloys [2,6], the T C value of A 1 is coincident with that of D 1 , however, it must be noted that the former is a fine eutectic while the latter shows a needle-like morphology. For x = 35, in addition to the magnetic transition at T C = 226 • C, another transition at around T C = 10 • C is observed, this temperature corresponds to the Pr 2 Fe 17 (2:17) phase [8].…”

“…The presence of the D 1 phase (T C = 245 • C and I H C = 2.2 kOe for RE = Nd, and T C = 230 • C and I H C = 2.1 kOe for RE = Pr at room temperature) was reported in thermomagnetic and microstructural studies of RE 80 Fe 15 (B 1−x C x ) 5 alloys annealed at 600 • C for x = 1.0 [1,2]. This phase is different from the RE 2 Fe 14 C phase (φ-phase) formed at temperatures slightly higher (above 800 • C) [3].…”

“…In the magnetic analyses carried out in these alloys, it was established that the metastable fine eutectic A 1 is the main magnetic phase formed in as-cast alloys in the whole composition range. Minor amounts of the phase designated to as A 3 (T C = 292 • C for RE = Nd, and T C = 260 • C for RE = Pr), which has been tentatively described as a monoclinic modification of φ [4], were also detected up to x = 0.90 [1][2][3][4][5][6]. The high uniaxial magnetic anisotropy of the D 1 phase was inferred from the temperature dependence behavior of coercivity at low temperatures ( I H C = 44.6 kOe at 4.2 K, for RE = Pr) [6].…”

“…For the experimental conditions reported in Refs. [2,6] it was also determined that in both alloy systems, C does not become incorporated into A 1 , A 3 RE 2 Fe 17 or the φ phases. The D 1 phase is believed to be a needle-like phase.…”