Nanocomposites and nanomaterials

Composition, structure and magnetic properties of DyxBi1-xFeO3 thin films
Makoed I.I.1, Galyas A.I.2, Yanushkevich K.I.2, Liedienov N.A.3, 4, Pashchenko A.V.3, 4, 5, 6, Bychkov K.L.7
1 Department of Physics, Brest State University. Kosmonavtov Ave., 21, Brest-224016, Belarus.
2 Institute of Solid State and Semiconductor Physics, National Academy of Sciences of Belarus. P. Brovki Str., 19, Minsk-220072, Belarus.
3 International Centre of Future Science, State Key Laboratory of Superhard Materials of Jilin University. Qianjin Str., 2699, Changchun-130012, China.
E-mail: nikita.ledenev.ssp@gmail.com
4 Phase Transitions Department, Donetsk Institute for Physics and Engineering named after O. O. Galkin, NASU. Prospect Nauki, 46, Kyiv-03028, Ukraine.
5 Donetsk National University of Economy and Trade named after Michael Tugan - Baranovsky. Ostrowski Str., 16, Kryvyi Rih-50005, Ukraine.
6 Institute of Magnetism NASU and MESU. Acad. Vernadsky Ave., 36-b, Kyiv-03142, Ukraine.
7 Taras Shevchenko National University of Kyiv. Lva Tolstoho Str., 12, Kyiv-01030, Ukraine.

Homogeneous DyxBi1-xFeO3 (x = 0 ‒ 0.20) thin films have been synthesized by thermal vacuum deposition method. The thickness of the films whose surface has a well-defined granular structure varies within 100 ‒ 500 nm. The films are crystallized in a monoclinic crystal lattice unlike bulk samples which have R3c (0 < х < 0.15) and Pnma (х = 0.15, 0.20) structure. Open magnetic hysteresis loops reach saturation in magnetic field 1.5 kOe at room temperature confirming the presence of ferromagnetic ordering. Saturation magnetization at Т = 5 K is not reached even at field 30 kOe. The replacement of Bi3+ by Dy3+ ions leads to HC coercive force changing its maximum value for the sample with x = 0.10 reaches 0.6 kOe (5 K) and decreases to 0.4 kOe (300 K). Residual magnetization and saturation magnetization increase with increasing the degree of substitution and their maxima for x = 0.15 are observed at both low and high temperatures.