Neutron Scattering for Antiferromagnetic γFe_0.7Ni_0.15Cr_0.15 Alloy (Non Magnetic Stainless Steel)

Abstract

The antiferromagnetic structure of a γFe_0.7Ni_0.15Cr_0.15 has been investigated with a triple axis neutron spectrometer. The magnetic scattering has been observed at 4.2 K around both the (110) and (001) reciprocal lattice points. It has been found that the 110 scattering is a pure Bragg reflection which disappears at T_N of 26±1 K. On the other hand, the 001 scattering was found to be purely quasi-elastic scattering, the profile of which depends strongly on the incident neutron energy. The results suggest that γ-Fe–Ni–Cr has a long range antiferromagnetic order of γ-Mn type with a sublattice magnetic moment of 0.3±0.1 μ_B per atom aligned along the [001] direction. The components of spins perpendicular to the [001] axis have only a short range correlation and they fluctuate in time even at 4.2 K. The results for neutron scattering in a magnetic field of 47 kOe suggest that the induced moment can be interpreted by the canting of the antiferromagnetic spins in the field direction.