Effect of magnetic field on the modulated spin structure of terbium manganite film
B.Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine,Kharkiv 61103, Ukraine
Received February 1, 2021, published online May 26, 2021
The first-harmonic approximation of the Ginzburg–Landay theory was used to analyze the influence of magnetic field H along the y axis (modulation direction of manganese spins) in incommensurate AFM phases in the orthorhombic TbMnO3 film. It was shown that an increase in magnetic field and a decrease in the film thickness lead to the decrease in the Néel temperature. The dependence of the Néel temperature on magnetic field in the TbMnO3 film was obtained. The boundary lines between modulated AFM phases in magnetic field are changed weakly besides some increase in the temperature Tc = 28 K at H = 0. It means the conservation of the colossal magnetoelectric effect of the “polarization flop in magnetic field” in the manganite terbium films up to 6 nm thickness. Therefore, such TbMnO3 films (3 periods of the spin cycloid) can become a basis of future nanotechnology of the magnetoelectric devices.
Key words: antiferromagnetic, incommensurate structure, ferroelectromagnet, film, magnetic field.