O and H diffusion has been investigated at a temperature of 300 °C in the double perovskite material PrBaCoO (PBCO) in flowing air containing 200 mbar of HO. Secondary ion mass spectrometry (SIMS) depth profiling of exchanged ceramics has shown PBCO still retains significant oxygen diffusivity (~1.3 × 10 cms) at this temperature and that the presence of water (HO), gives rise to an enhancement of the surface exchange rate over that in pure oxygen by a factor of ~3. The H distribution, as inferred from the HO SIMS signal, shows an apparent depth profile which could be interpreted as H diffusion. However, examination of the 3-D distribution of the signal shows it to be nonhomogeneous and probably related to the presence of hydrated layers in the interior walls of pores and is not due to proton diffusion. This suggests that PBCO acts mainly as an oxygen ion mixed conductor when used in PCFC devices, although the presence of a small amount of protonic conductivity cannot be discounted in these materials.
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http://dx.doi.org/10.1080/14686996.2017.1402661 | DOI Listing |
J Phys Chem Lett
January 2025
Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States.
Lead-free halide double perovskites (DPs) have become a research hotspot in the field of photoelectrons due to their unique optical properties and flexible compositional tuning. However, the luminescence of DPs exhibits thermal quenching at high temperatures, which severely affects their further application. Herein, we synthesized the rare earth Dy and transition metal Mn codoped CsNaYCl rare earth DPs and characterized the optical properties using temperature-dependent photoluminescence spectra and time-resolved photoluminescence decay profiles at different temperatures.
View Article and Find Full Text PDFJ Phys Condens Matter
January 2025
School of Materials Science, Indian Association for the Cultivation of Science, Calcutta 700 032, Kolkata, West Bengal, 700032, INDIA.
An exotic quantum mechanical ground state, i.e. the nonmagnetic= 0 state, has been predicted for higher transition metal tsystems, due to the influence of strong spin-orbit coupling (SOC) or in other words, due to unquenched orbital moment contribution.
View Article and Find Full Text PDFJ Mol Model
January 2025
Department of Physics, Faculty of Sciences, Shahrekord University, P.O. Box 115, Shahrekord, Iran.
Context: Exploration for renewable and environmentally friendly energy sources has become a major challenge to overcome the depletion of fossil fuels and their environmental hazards. Therefore, solar cell technology, as an alternative solution, has attracted the interest of many researchers. In the present work, the CsXInBr (X = Cu or Ag) compounds as lead-free halide perovskites have been studied due to their direct energy gap in the range of solar energy, thermodynamic stability, low effective mass of electrons, and high absorption coefficient.
View Article and Find Full Text PDFChem Sci
December 2024
Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystal, College of Materials Science and Engineering, Tianjin University of Technology Tianjin 300384 China
Non-centrosymmetric (NCS) compounds can exhibit many symmetry-dependent functional properties, yet their rational structure design remains a great challenge. Herein, a strategy to introduce F-centered octahedra to construct a perovskite-type framework filled by π-conjugated [BO] dimers is proposed to obtain NCS compounds. The first examples of antiperovskite or double antiperovskite borate fluorides, [(M/Ba)Ca]F[BO] (M = K, Rb) and [CsBaCa]F[BO], have been successfully designed and synthesized.
View Article and Find Full Text PDFSci Rep
January 2025
Multifunctional Materials Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India.
The utilization of single crystals is exponentially growing in optoelectronic devices due to their exceptional benefits, including high phase purity and the absence of grain boundaries. However, achieving single crystals with a porous structure poses significant challenges. In this study, we present a method for fabricating porous single crystals (porous-SC) of CsAgBiBr and related halide double perovskites using an infrared-assisted spin coating technique.
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