Magnetic Properties of Iron Nitride Thin Films Prepared by the Magnetron Discharge Method

The saturation magnetization M
_s
of polycrystalline iron thin films increased by approximately 10% after films were subjected to ion nitriding treatment for about one hour. In the latter treatment, the magnetron discharge method was used to increase the energy density of the discharge. The rate of increase of M
_s
was 21.2% after the iron thin film was nitrided under an N
₂
gas pressure of 4.5×10
^-2
Torr. X-ray diffraction studies revealed the presence of Fe
₁₆
N
₂
, γ'-Fe
₄
N, ε-Fe
₃
N, ζ-Fe
₂
N, and α-Fe phases in thin films nitrided under various N
₂
gas pressures. The saturation magnetization M
_s
of Fe
₁₆
N
₂
, calculated using X-ray integrated intensity ratios, was 2210 emu/cc in nitrided thin films under an N
₂
gas pressure of 4.5×10
^-2
Torr, and the M
_s
of Fe
₁₆
N
₂
, calculated using X-ray integrated intensity ratios, was 1710 emu/cc for thin film nitrided under an N
₂
gas pressure of 7.5×10
^-2
Torr.