Polarized neutron reflectometer: A new instrument to measure magnetic depth profiles

Abstract

A description is given of the prototype polarized neutron reflectometer installed at the intense pulsed neutron source. This instrument is designed for determining the magnetic depth profiles near the surfaces of ferromagnets and superconductors, by measuring the spin-dependent reflectivities of a well-collimated (0.01°) beam of cold neutrons from surfaces of a few cm2. Magnetic profiles can be determined with the spatial resolution of 40 Å, over thicknesses up to 5000 Å. Variations of the magnetic flux of the order of 10−5 G cm2 can be detected.

Influence of in-plane crystalline quality of an antiferromagnet on perpendicular exchange coupling and exchange bias

“…Polarized neutron reflectometry ͑PNR͒ involves specular reflection of a polarized neutron beam from a flat sample onto a polarization analyzer. 29 Four neutron cross sections were measured. Two cross sections correspond to the non-spin-flip ͑NSF͒ reflectivity profiles, where the intensities of the reflected radiation for spin-up ͑ϩϩ͒ ͓and alternately spin-down ͑ϪϪ͔͒ neutrons illuminating and reflecting from the sample were measured.…”

Antiferromagnetic dipolar ordering in[Co2MnGe∕V]Nmultilayers

“…(4.56) and (4.57) shall not be given here, but several algorithm to simulate PNR data have been provided in the literature [141,142,143], among them the supermatrix (SM) method and the matrix-recursion (MR) formalism [144,145,146,147,148]. The latter one is based on a generalized Parratt formalism.…”

Depth Profile of Uncompensated Spins in an Exchange Bias System

“…We undertook a polarized neutron reflectometry [27,28] study with polarization analysis to determine whether the spatial variation of the net magnetization vector [29] in the Co and FeF 2 layers could be attributed to a domain wall parallel to the Co=FeF 2 interface, and to obtain the depth profile of the pinned magnetization. After cooling the sample to 10 K in a 438 kA=m field along [001] FeF 2 (to establish bias), we rotated the sample about its surface normal in this field, so that H was parallel to 110 FeF 2 (Fig.…”