Abstract
The complex crystal and magnetic structure of strontium-doped ytterbium manganites using high-resolution neutron diffraction at low temperature starting from 2.6 K has been studied. Yb0.6Sr0.4MnO3 was crystallized with the mixed phases of crystal structure: orthorhombic with Pbnm space group enclosing Jahn-Teller Mn3+ ions, and hexagonal crystal system of P6(3)cm space group describing JT ions free phase over the whole temperature range. From the refinement of the neutron diffraction patterns, a distinguished difference in the behaviors of the two phases was observed with a variation in temperature where opposite lattice-temperature-dependent behavior was found. The magnetic ordering in hexagonal symmetry was frustrated and was having a canted spin of Mn magnetic moments in the plane of the Gamma 2-type symmetry. Mn ions were arranged together in the well-separated triangular layers parallel to (ab) plane as a result of the antiferromagnetic exchange interaction between the spins of atoms in the most nearest neighbors, which make the Mn spin subsystem of low-dimensional and frustrated at T-N approximate to 150 K. The other phase of the orthorhombic crystal system showed the C-type antiferromagnetic at T-N approximate to 70 K. The contribution of Yb atom in the magnetic ordering down to T = 2.6 K has not been registered. The magnetization-temperature dependence of Yb0.6Sr0.4MnO3 at different applied magnetic field was calculated using Monte Carlo simulation based on Ising model. Theoretically calculated model and experimental data were in good agreement. The complex magnetic ordering of the Yb0.6Sr0.4MnO3 for the mixed crystal structure was well described by Ising model.