Phase transitions in TbMnO₃ manganites

• Published in: Физика низких температур
• Date: 2012
• Main Authors: Dyakonov, V., Szytuła, A., Szymczak, R., Zubov, E., Szewczyk, A., Kravchenko, Z., Bażela, W., Dyakonov, K., Zarzycki, A., Varyukhin, V., Szymczak, H.
• Format: Article
• Language: English
• Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2012
• Subjects: Низкотемпеpатуpный магнетизм
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/116948
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Phase transitions in TbMnO₃ manganites / V. Dyakonov, A. Szytuła, R. Szymczak, E. Zubov,A. Szewczyk, Z. Kravchenko, W. Bażela, K. Dyakonov,A. Zarzycki, V. Varyukhin, H. Szymczak // Физика низких температур. — 2012. — Т. 38, № 3. — С. 273-277. — Бібліогр.: 19 назв. — англ.

X-ray diffraction and magnetic measurements of polycrystalline and nanosize TbMnO₃ manganites have been
 performed. All the compounds studied crystallize in the orthorhombic crystal structure (space group Pnma) at
 room temperature. The nanosize manganites were synthesized with a sol-gel method at different (800 and
 900°C) temperatures. The average size of synthesized nanoparticles (from 45 to 70 nm) was estimated by using
 the x-ray diffraction and low-temperature adsorption of argon methods. An information on the evolution of
 properties of TbMnO₃ with changing grain size, temperature and magnetic field was obtained. The crystal structure
 parameters of nanospecimens change slightly with changing the nanoparticle size. The peculiarities of magnetic
 ordering in polycrystalline and nanosize TbMnO₃ were compared. Magnetization and the Nèel temperature
 corresponding to antiferromagnetic ordering of the Tb³⁺ sublattice decrease as the particle size is reduced. The
 inverse magnetic susceptibility of the nanoparticle samples deviates from the Curie–Weiss law below 50 K, that
 is connected with the magnetic ordering of the Mn³⁺ moments. Specific heat of the nanosize samples exhibits
 anomalies related to the magnetic ordering of the Tb³⁺ and Mn³⁺ sublattices.