First-principles based Monte Carlo modeling of the magnetization of oxygen-deficient Fe-substituted SrTiO₃

Abstract

Transition-metal (TM) substituted SrTiO$_{3}$ has attracted much attention because its magnetism and/or ferroelectricity can be tuned via cation substitution, point defects, strain and/or oxygen deficiency. For example, Goto et al....

Room-Temperature, Nanoscale Multiferroic Pb(Fe0.5Ta0.5)1−x(Zr0.53Ti0.47)xO3 (x = 0.2, 0.3) Thin Films Grown via the Pulsed Laser Deposition Technique

“…The dielectric constant ε r broadened over a wider temperature range from 400 to 600 K due to the statistical distribution of relaxation times in that temperature window. This indicates that the materials exhibited a diffuse ferroelectric phase transition (DPT) at elevated temperatures [24][25][26][27]. The variation in the loss tangent (tan δ) with temperature was almost flat from 100 to 400 K and increased suddenly with an increasing temperature above 400 K. As the mobility of oxygen vacancies increases at high temperatures, one can expect their contribution to ionic conductivity to occur in thin-film capacitors above 400 K. Hence, the increasing trend of the loss tangent above 400 K can be attributed to the contribution from ionic conductivity [26,28,29].…”

“…To be precise, γ = 1 corresponds to a normal ferroelectric transition and γ = 2 corresponds to a total diffuse ferroelectric transition. On the other hand, the range of values 1 ≤ γ ≤ 2 represents an incomplete diffuse ferroelectric transition [24]. To perform this exercise, dielectric data at 10 kHz above the dielectric maximum temperature Tm were considered.…”

“…Oxygen vacancies and strain were found to play significant roles in determining the structural, magnetic, refs. [23,24], and ferroelectric properties [24] of the thin films.…”

Study of the magnetism of C-doped MgO based on first-principles calculations and the Ising model

“…Magnetization of cation substitution, point defects, strain and/or oxygen deficient-perovskite, such as oxygen-deficient Fe-substituted SrTiO 3 , has been studied by a first-principles based Monte Carlo model, and it showed that the first-principles based Monte Carlo model provides guidelines for predicting magnetization in complex oxides with point defects. 22…”