Synthesis of single nanocrystal phase γ′-Fe4N on NaCl substrate by DC magnetron sputtering

Investigation of γ′-Fe4N thin films deposited on Si(1 0 0) and GaAs(1 0 0) substrates by facing target magnetron sputtering

“…In other words, the disordered moments at the grain boundaries and film surface were frozen at the low temperatures so that the relative large Hc appears due to the pinning effect of the moments [3,18]. Further, based on the Bloch's spin wave theory, Ms will satisfy the following relation [17,19],…”

“…Due to the neglect of the interaction between the spin waves, formula (2) can be used to fit the experimental data in the low-temperature range. After that, this formula was modified by considering the scattering between the spin waves, as following [17,19],…”

“…Among them, single face γ 0 -Fe 4 N films have been obtained on different substrates such as Si (1 0 0), NaCl(1 0 0), Cu(1 0 0), MgO(0 0 1) and SrTiO 3 (0 0 1) substrates [5,[15][16]. Recently, Wang et al [17][18][19] investigated the influence of substrate materials such as NaCl(1 0 0), Si(1 0 0) and glass on the magnetic properties of γ 0 -Fe 4 N thin films. They found that Ms of the films on different substrates had almost the same value, but Hc of the films was different between single-crystal substrate and amorphous substrate.…”

Antiperovskite Magnetic Materials with 2p Light Elements for Future Practical Applications

“…The decomposition temperature is near 680 K, indicative of a higher phase stability. While γ ′-Fe 4 N powder can be synthesized by nitridation using ammoniahydrogen gas, [55] single phase γ ′-Fe 4 N thin films can be successfully grown not only on MgO substrates but also SrTiO 3 [44] and NaCl [45] crystal substrates using MBE [40][41][42] and various sputtering techniques, including ion-beam sputtering, [43] DC/RF reactive sputtering, [44][45][46] facing-target sputtering, [47,48] and highpower impulse magnetron sputtering. [49] To boost the degree of order of N (S) in Fe 4 N films, a (001) plane is indispensable as an underlayer.…”

“…γ ′-Fe 4 N is a ferromagnet with a Curie temperature of 767 K and saturation magnetization (M s ) of ≈1.8 T; it is a stable compound at room temperature, enabling successful thin film growth using molecular beam epitaxy (MBE) [40][41][42] and various sputtering techniques. [43][44][45][46][47][48][49][50] The density of states revealed by first-principles calculations suggests negative spin polarization at the Fermi level [P DOS (E F )]. [51][52][53] As a result, the inverse TMR ratio at room temperature could be as large as −76% for Fe 4 N/MgO/CoFeB-based magnetic tunnel junctions (MTJs).…”