Dielectric, magnetic, and thermodynamic properties of Y1−xSrxMnO3 (x = 0.1 and 0.2)

Abstract

We report the effect of strontium (Sr) doping on dielectric, magnetization, and thermodynamic properties of polycrystalline Y1−xSrxMnO3 (x = 0.1, 0.2) samples prepared by conventional solid-state reaction method. The temperature dependent dielectric permittivity and specific heat curves noticeably show the anomalies near its magnetic transition point, i.e., Neel temperature (TN), which are probably generated by the frustrated Mn3+ spins (S = 2) on a triangular Mn lattice showing the magneto-electric coupling between the electric and magnetic orders. However, the magnetic transition is not clearly evident in the magnetic susceptibility due to the frustration on the Mn triangular lattice and the dominating paramagnetic susceptibility of the Y3+ spins. The electronic transport mechanism in these materials was analyzed within the framework of conventional Arrhenius Law, i.e., ρ(T) = C exp(Ea/kBT) applied to low frequency ac resistivity data, and through the peak method employed to the permittivity and loss tangent by using equation f = f0 exp(−Ea/kBTp), suggests simple thermal activation. The effect of induced Mn4+ ions in the crystal lattice with doping of Sr2+ ion on transport properties has been discussed in details.

Oxygen Nonstoichiometry and Defect Equilibria of Yttrium Manganite Perovskites with Strontium A-Site and Aluminum B-Site Doping

“…For YSMA8264, changes in the PXRD patterns were observed after both Ar- and H 2 -reduction. After reduction in Ar at 1173 K, new peaks exist at 28.87, 29.94, 31.19, 51.4, and 56.74°; each of these peaks is present in Y 0.8 Sr 0.2 MnO 3 (PXRD patterns for which are shown in Figure S6 of the Supporting Information), which crystallizes to a hexagonal non-perovskite structure. , After reduction in H 2 , the low-intensity peaks at 28.87, 29.94, and 31.19° are no longer visible, and a relatively high intensity peak at 28.99° can be seen. Additionally, notable separation of the main Bragg peak was observed for the H 2 -reduced YSMA8264 sample.…”

Thermodynamic Properties of La1-xSmxCoO3

“…The effective interionic potential corresponding to the modified rigid ion model (MRIM) frame work is expressed as [9,10]…”

“…The symbol is the crystal structure constant, 0 is the equilibrium nearest neighbor distance of the basic perovskite cell, and is the bulk modulus. The cohesive energy for La 1− Sm CoO 3 (0 ≤ ≤ 0.2) is calculated using (1) and other thermal properties such as the Debye temperature ( ), Reststrahlen frequency ( ), molecular force constant ( ), Gruneisen parameter ( ), specific heat ( ), and thermal expansion ( ) are computed using the expressions given in [9,10]. The results are thus obtained and discussed below.…”

“…Recently, we have applied the modified rigid ion model (MRIM) to study the specific heat of cobaltates and manganites [9,10]. Motivated from the applicability and versatility of MRIM, we have applied MRIM to investigate the temperature dependence of the specific heat, thermal expansion, and elastic and thermal properties of La 1− Sm CoO 3 (0 ≤ ≤ 0.2).…”

Modulation of the Structural, Magnetic, and Dielectric Properties of YMnO3 by Cu Doping

“…The change in the tilting of the MnO 5 trigonal bipyramid can be tuned by doping ions with distinct radii and variable valences at the Y or Mn sites. Many studies have been conducted on dielectric behaviors, electrical properties, and magnetic properties of YMnO 3 by replacing the elements like Sr, Ca, Dy, Lu, Gd, or Zr at the Y site, or Mn, Mn, Al, Co, Ti, etc., at the Mn site [ 10 , 11 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. For instance, when doping with Lu at the YMnO 3 Y site, the dielectric constant achieved the pinnacle within the solid solution area, but the Curie temperature did not alter [ 27 ].…”