Investigation of structural, optical and electrical properties of Sr₂SnO₄, Sr_1.99Eu_0.01SnO₄ and Sr₂Sn_0.99Eu_0.01O₄ Ruddlesden Popper oxide

Structural, electrical and optical properties of samples have been reported in this paper. The samples with compositions Sr₂SnO₄, Sr_1.99Eu_0.01SnO₄ and Sr₂Sn_0.99Eu_0.01O₄ are prepared by solid state ceramic route followed by calcination at temperature 1000 °C for 8 h. Rietveld refinement of powder x-ray diffraction (XRD) data showed tetragonal structure in all samples with space group (I4/mmm). X-ray photoelectron spectroscopy (XPS) studies indicate the presence of Sn in Sn⁴⁺ and Sn²⁺ state in both the samples. The electrical conductivity of the sample follows universal johnscher's law.'$\sigma ={\sigma }_{dc}+A{\omega }^n$'. Temperature dependent electrical conductivity shows Arrhenius type charge transport in samples Sr₂SnO₄, Sr_1.99Eu_0.01SnO₄ and Sr₂Sn_0.99Eu_0.01O₄ with activation energy 0.16, 0.17, 0.16 eV respectively. Conduction in these sample occurs via electron hopping through the multivalent state of Sn, $S{n}^{4+}/S{n}^{2+}.$ Conductivity spectra obtained at different temperature scaled by Ghosh Scaling $\frac{{\sigma }^{\prime }\left(f\right)}{{\sigma }_{dc}}=F\left(\frac{f}{f_H}\right)$ perfectly follows time temperature superposition principle (TTSP). The presence of Eu is further probed by photoluminescence (PL) spectroscopy in which emission spectra of Eu³⁺ for both the samples show intense emission peak at 577, 595 and 612 nm assigned to transitions from ⁵D₀ → ⁷F_J (J = 0, 1, 2, 3) levels of Eu³⁺. Higher the value of conductivity σ _dc and integrated area of emission peak for Sr_1.99Eu_0.01SnO₄ is making it more multifunctional than Sr₂Sn_0.99Eu_0.01O₄. (paper)