Combined neutron and synchrotron studies

of magnetic films

SUNIL K SINHA^1,2, S ROY¹, M R FITZSIMMONS², S PARK², M DORN³,

O PETRACIC^1,3, I V ROSHCHIN¹, ZHI-PAN LI¹, X BATLLE^3,4,

R MORALES^1,5, A MISRA², X ZHANG², K CHESNEL⁶, J B KORTRIGHT⁶ and IVAN K SCHULLER¹

¹Department of Physics, University of California at San Diego, La Jolla, CA 92093, USA

²Los Alamos National Laboratory, Los Alamos, NM 87545, USA

³Angewandte Physik, Universit\"at Duisburg-Essen, 47048 Duisburg, Germany

⁴Departament de Fisica Fonamental, Universitat de Barcelona, 08028 Barcelona, Catalonia, Spain

⁵Departamento de Fisica, Universidad de Oviedo, c/Calvo Sotel s/n, Oviedo 33007, Spain

⁶Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA

E-mail: ssinha@physics.ucsd.edu

Abstract. We discuss specular reflectivity and off-specular scattering of

neutrons and X-rays from magnetic films. Both these techniques are capable

of providing information about the morphology of the chemical and magnetic

roughness and the magnetic domain structure. The use of neutrons with

polarization analysis enables the spatial distribution of different vector

components of the magnetization to be determined, and the use of resonant

magnetic X-ray scattering enables magnetization in a compound system to be

determined element-selectively. Thus both these methods provide powerful and

complementary new probes for studying magnetism at the nanoscopic level in a

variety of systems such as those exhibiting exchange bias, giant

magnetoresistance, spin injection, etc. We shall illustrate with an example

of both techniques applied to an exchange bias system consisting of a single

crystal of antiferromagnetic FeF$_2$ capped with a ferromagnetic Co film, and

discuss what has been learned about how exchange bias works in such a system.

Keywords. Neutron reflectometry; X-ray reflectometry; magnetic films.

PACS Nos 61.12.H; 61.10.K; 75.70.K