New Magnetic Material Having Ultrahigh Magnetic Moment

Abstract

The change of the saturation magnetization of Fe films with the pressure of nitrogen during deposition ranging from 2 × 10−5 to 7 × 10−3 Torr has been investigated systematically. We found a new magnetic material which has the highest saturation magnetization at room temperature, 2050 G, among those of all the magnetic materials. This was attributed to Fe16N2, which has a bct structure, and the magnetic moment associated with Fe atoms of Fe16N2 was deduced to be 3.0 μB.

Effects of alloying and strain on the magnetic properties of Fe16N2

“…2 This result was not independently confirmed until twenty years later. 3 Owing to the rapid development of the magnetic recording technologies, this confirmation inspired numerous studies of thin-film samples.…”

“…In particular, measurements of T C are hampered by the decomposition of the metastable Fe 16 N 2 into Fe 4 N and Fe, which was reported to occur above 200 • C, 6 in the 230-300 • C range, 2 or at 400 • C. 3 Sugita et al extrapolated their data to estimate T C at 540 • C. 3 Thermal stability of Fe 16 N 2 was reported to increase with addition of Co and Ti 16,17 (up to 700 • C in the Ti case). However, no experimental information is presently available about the T C of Co or Ti-doped Fe 16 N 2 , or of any other Fe 16 N 2 samples stabilized at high temperatures.…”

Magnetic and electrical properties of iron nitride films containing both amorphous matrices and nanocrystalline grains

“…The magnetic properties are also changed by the nitrogen concentration in the iron nitride. For example, the saturation magnetizations of the a 0 -Fe x N (x $ 8; 4pM s ¼ 22 -24 kG) [6] and the a 00 -Fe 16 N 2 ð4pM s ¼ 28 -30 kGÞ [7] phases are higher than that of the a-Fe ð4pM s ¼ 21:6 kGÞ phase. The saturation magnetizations of the g 0 -Fe 4 N ð4pM s ¼ 18 -21 kGÞ [8] and the 1-Fe 3 N ð4pM s ¼ 16 -17 kGÞ [9] phases are lower than that of the a-Fe phase.…”

Nanoscale Iron Nitride, ε-Fe3N: Preparation from Liquid Ammonia and Magnetic Properties

“…8 They are cheap and exhibit high saturation magnetization and very high magnetic moments. 4,6 The investigation of their interesting magnetism is hindered by the difficulty to prepare magnetically pure phases in sufficiently large quantities. A recent review discusses the synthesis and properties of iron nitrides at reduced dimensions.…”

“…Iron nitrides show exceptional physical properties [2][3][4][5] that can be used for various applications such as magnetic recording media, 5,6 catalysis, 7 and biomedical applications. 8 They are cheap and exhibit high saturation magnetization and very high magnetic moments.…”