|
Pis'ma v Zhurnal Èksperimental'noi i Teoreticheskoi Fiziki, 2006, Volume 83, Issue 11, Pages 568–572
(Mi jetpl1315)
|
|
|
|
This article is cited in 5 scientific papers (total in 5 papers)
FIELDS, PARTICLES, AND NUCLEI
Investigation of the chiral structure of the Y/Dy multilayer system by the method of the small-angle scattering of polarized neutrons
S. V. Grigor'eva, A. I. Okorokova, Yu. O. Chetverikova, D. Yu. Chernysheva, H. Eckerlebeb, K. Pranzasb, A. Schreyerb a Petersburg Nuclear Physics Institute, Russian Academy of Sciences
b GKSS Forschungszentrum, 21502 Geesthacht, Germany
Abstract:
The magnetic spiral structure of a Y/Dy sample has been investigated for temperatures from 30 to 190 K by the method of the small-angle scattering of polarized neutrons. The sample is a sequence of layers Y50nm [Dy4.3nm /Y2.8nm ]350/Y234nm /Nd200nm Al2O3 (substrate) that is grown as a single crystal with the [001] axis of the hexagonal lattice, which is perpendicular to the layer plane. The experiments demonstrate the appearance of the magnetic peak below T N = 165.4 K, which is associated with the helicoidal phase, and the helicoid coherence length is larger than the layer thickness of the Y/Dy layer. The use of polarized neutrons allows the separation of the polarization-independent and polarization-independent components of magnetic scattering. The polarization-independent component of the magnetic neutron cross section is proportional to magnetization squared 〈;S Z 〉2, whereas the polarization-dependent component is proportional to the average chirality of the system 〈;C〉 = 〈;[·S 1 × S 2]〉. The critical exponents βC = 1.02(1) and β = 0.39(1) have been determined for the average chirality and magnetization, respectively. The magnetization critical exponent β for Dy/Y coincides with the exponent obtained for Dy bulk samples. The difference βC − 2β = 0.24(2) shows that the chirality can be a component of the order parameter that is independent of magnetization. This experiment corroborates the results that were obtained for the critical chirality in Ho and were reported in Phys. Rev. B 64, 100402(R) (2001).
Received: 24.04.2006
Citation:
S. V. Grigor'ev, A. I. Okorokov, Yu. O. Chetverikov, D. Yu. Chernyshev, H. Eckerlebe, K. Pranzas, A. Schreyer, “Investigation of the chiral structure of the Y/Dy multilayer system by the method of the small-angle scattering of polarized neutrons”, Pis'ma v Zh. Èksper. Teoret. Fiz., 83:11 (2006), 568–572; JETP Letters, 83:11 (2006), 478–482
Linking options:
https://www.mathnet.ru/eng/jetpl1315 https://www.mathnet.ru/eng/jetpl/v83/i11/p568
|
Statistics & downloads: |
Abstract page: | 222 | Full-text PDF : | 65 | References: | 33 |
|