Yu. V. Nikitenko

Neutron interference at grazing incidence reflection. Neutron standing waves in multilayered structures: Applications, status, perspectives

Possibilities of creating a field of neutron standing waves (NFSW) in a layered nanostructure for the purposes of formation and analysis of the neutron beam and investigation of the properties of the structure itself are discussed. The status of investigations of such neutron wave fields is formulated and directions of their possible application are indicated. The results of investigations in the regimes of neutron standing waves and enhanced neutron standing waves with a specified neutron spin state carried out at the pulsed reactor IBR-2 using different registration channels are presented. The high sensitivity of NFSW for structural investigations is noted.

Spin-flip spatial neutron beam splitting in magnetic media

Possible uses of the effect of beam splitting for investigations of magnetic media, formation of neutron beams and measurements of their characteristics are discussed. The results of experimental investigations of magnetic layers and layered structures are presented. The application of the effect for the determination of the parameters of uniformly magnetized magnetics and magnetics with a domain structure is noted as perspective.

Neutron standing waves in layered systems: Formation, detection, and application in neutron physics and for investigation of nanostructures

Specific features of different regimes of the neutron’s wave field are theoretically considered. The results of experimental studies of the regime of a neutron’s standing waves both in the primary channel of neutron specular reflection and in different channels of registration of secondary emission are considered. Some studies of layered structures performed with the help of a neutron’s standing waves are considered. The prospects of application of a neutron’s standing waves in neutron physics and for investigation of layered nanostructures are considered.

Neutron standing waves in layered systems

A theory of propagation of neutron waves in multilayer magnetic and nonmagnetic systems is presented. It is shown how a system forms the wave function of a neutron, how the wave function formed can be controlled, and how this function can be used to investigate materials. The results of experimental investigations of the neutron reflection from multilayer systems with simultaneous measurement of different types of secondary radiation are reported.

Magnetic non-collinear neutron wave resonator

Abstract Equations for the neutron reflection amplitude from a magnetic non-collinear wave resonator (NWR) are obtained. It is shown that resonances of the same reflection order of neutrons experiencing spin-flip (spin-flip neutrons) appear in pairs. Conditions, under which resonator square enhancement of the spin-flip neutron reflection intensity with respect to growth of the portion of scattered and absorbed neutrons takes place, are determined.

Layered structures as elements of the neutron spin-echo reflectometer

The specific features of neutron reflection and transmission through layered magnetic nanostructures are discussed. The possibility of using layered magnetic nanostructures as elements or combinations of the elements of the spin-echo spectrometer is demonstrated.

Refraction of polarized neutrons in a magnetically non-collinear layer

Abstract The refraction of polarized neutrons in a magnetic layer in relation to the neutron wavelength, the magnitude and direction of an external magnetic field, has been investigated experimentally. The effects of space splitting of the polarized neutron beam and the interference of neutron beams with different spin states have been observed and measured.

Neutron channeling in layered Cu/Ti/Cu structures

The phenomenon of neutron channeling in layered structures is considered. Experimental data for the neutron channeling length in layered Cu/Ti/Cu structures obtained in Dubna (Russia) and Grenoble (France) in 2000–2002 are presented. A conclusion about the necessity of further studies of neutron channeling in multilayer structures is drawn.

System of neutron microbeams from a planar waveguide

Results of experimental investigations of space, angular and wavelength distribution in neutron microbeams obtained for the first time with the help of a resonant planar neutron waveguide at the time-of-flight reflectometer of the IBR-2 pulsed reactor are reported and comparison with theoretical calculations is presented. Possible application of microbeams in physical experiments is discussed.

On the Feasibility to Study Inverse Proximity Effect in a Single S/F Bilayer by Polarized Neutron Reflectometry ¶

Here we report on a feasibility study aiming to explore the potential of Polarized Neutron Reflectometry (PNR) for detecting the inverse proximity effect in a single superconducting/ferromagnetic bilayer. Experiments, conducted on the V (40 nm)/Fe (1 nm) S/F bilayer, have shown that experimental spin asymmetry measured at T = 0.5TC is shifted towards higher Q values compared to the curve measured at T = 1.5TC. Such a shift can be described by the appearance in superconducting vanadium of magnetic sublayer with a thickness of 7 nm and a magnetization of +0.8 kG.