Magnetic measurements of Fe–Ni–Nb–B and Fe–Co–Mo–Cu–B in the vicinity of the Curie temperature

Evolution of physical properties of amorphous Fe–Ni–Nb–B alloys with different Ni/Fe ratio upon thermal treatment

“…The dependencies of par (H) and perp (H) for different thermal treatments are shown in Fig. 2a-c. Magnetostriction measurements of as-quenched samples measured at room temperature indicate that the alloy with Ni/Fe = 0 is close to paramagnetic state (T C ∼ 80 • C) -the value of room-temperature S is nearly zero [8]. All compositions are ferromagnetic in amorphous state.…”

“…Both effects are due to the formation of the crystalline phases above 500 • C. For compositions with Ni/Fe = 0, 1/6 and 1/3 the crystalline phase formed during the applied thermal treatment is nanocrystalline bcc-Fe embedded in amorphous remains. For Ni/Fe = 1/1 the formation of fcc-Fe(Ni) and (Fe-Ni) 23 B 6 phases with small traces of bcc-Fe(Ni) was observed [8,9]. The dependencies of par (H) and perp (H) for different thermal treatments are shown in Fig.…”

“…Hysteresis loops of the investigated alloys measured after isothermal annealing at selected temperatures (400, 500 and 550 • C) are shown in Fig. 3a-d. The magnetic hysteresis loops essentially lost their as-cast character (poor saturation) [8] demonstrating substantial relaxation of the as-cast internal stresses during the 1 h 400 • C vacuum annealing - Fig. 3a.…”

Mössbauer Spectroscopy of Fe-Ni-Nb-B Alloy in Weak Magnetic Field

“…In the last years, alloys with crystallite sizes less than 100 nm have attracted attention due to some of their magnetic properties such as effective permeability and saturation magnetic flux density [5,6]. These properties indicate that these materials may have application in magnetic parts and devices such as inductors, low and high energy frequency transformers, alternating current machines, motors, generators, transducers, sensors and actuators [7,8].…”