1998 · 18 citations · 0 references
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The structure, magnetic and electronic transport properties of epitaxial Mn<sub>4</sub>N films fabricated by the facing-target reactive sputtering method have been investigated systematically. The high-quality growth of Mn<sub>4</sub>N films was confirmed by x-ray<i>θ</i>-2<i>θ</i>, pole figures and high-resolution transmission electron microscopy. The Mn<sub>4</sub>N films exhibit ferrimagnetic with strong perpendicular magnetic anisotropy. The saturation magnetization of Mn<sub>4</sub>N films decreases with increasing temperature, following the Bloch's spin wave theory. The resistivity of Mn<sub>4</sub>N films exhibits metallic conductance mechanism. Debye temperature of Mn<sub>4</sub>N is estimated to be 85 K. The calculated residual resistivity<i>ρ</i><sub><i>xx</i>0</sub>of the 78.8 nm-thick Mn<sub>4</sub>N film is 30.56<i>μ</i>Ω cm. The magnetoresistances of Mn<sub>4</sub>N films display a negative signal and butterfly shape. The sign of anisotropic magnetoresistance (AMR) is positive, which infers that the AMR is dominated by the spin-up conduction electrons. Moreover, the transformation of fourfold to twofold symmetry for AMR and twofold to onefold symmetry for planar Hall resistivity is attributed to tetragonal crystal field effect.