Atomistic mechanism of cyclic phase transitions in Nd–Fe–B based intermetallics

Size-dependent magnetic and magnetothermal properties of gadolinium silicide nanoparticles

“…The formation of this surface layer reduces the magnetization and at the same time increases the coercivity, as has been observed in core-shell nanoparticles. 24,25 Thus, by varying the milling time and milling speed, we are able to obtain a wide range of crystallite sizes (13-43 nm) with coercivities varying between 8 and 87 Oe and magnetization M @ 15 kOe in the range of 7-73 emu g À1 . To investigate the effect of milling time and milling speed on the Curie temperature (T C ), we measured the thermal demagnetization of BM-200-10 and BM-500-50 samples in the zero-eld-cooled (ZFC) mode in a static eld of 100 Oe in the temperature range 240-420 K. The results obtained are shown in Fig.…”

Phase transformation of the CuAl2 intermetallic alloy during high-energy ball-milling

“…Past investigation has shown that several ordered phases have structural transitions from low to high temperature phases [1]. As previously mentioned, it is important to note that the tetragonal CuAl 2 phase has not a high temperature phase in the equilibrium compositional diagram [9].…”

“…Previous researches have shown that intermetallic phases of equilibrium are energetically unstable under high-energy ballmilling [1,2]. In most cases, the intermetallic compounds transform into metastable phases during milling of elemental components to the same atomic composition [3e6].…”

“…In most cases, the intermetallic compounds transform into metastable phases during milling of elemental components to the same atomic composition [3e6]. In order to obtain metastable phase transformation, significant amounts of energy is stored in intermetallic phases [1,6,7]. For example, in the past [8] has been confirmed the formation of non-equilibrium phase body-centered cubic (bcc) starting from elemental powders for a chemical composition of Al-33.3% Cu, after 800 h milling.…”

Structural Evolution of FeAl₃ Intermetallic during High-Energy Ball-Milling

“…In the past, the mechanical milling (MM) process has been widely used to induce phase transformation of different ordered intermetallic compounds [1][2][3]. During the MM process, point defects occur which enhance the atomic diffusion and increases the enthalpy of the equilibrium phase to the point where the free energy is able to form a metastable phase related.…”