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Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
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Structural Phase Transitions and Superconductivity Induced in Antiperovskite Phosphide CaPd3P
Akira Iyo1, Hiroshi Fujihisa1, Yoshito Gotoh1
1National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 3058568, Japan.
Inorganic Chemistry
|August 27, 2020
Summary
Researchers synthesized new antiperovskite phosphides and found superconductivity in a Ca-Sr solid solution. The study explores the link between crystal structure symmetry and superconductivity in these novel materials.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Solid-State Chemistry
Background:
- Antiperovskite phosphides are a class of materials with potential for unique electronic properties.
- Understanding structure-property relationships, particularly concerning superconductivity and crystal symmetry, is crucial for materials discovery.
Purpose of the Study:
- To synthesize novel antiperovskite phosphides of the formula M M Pd3P (M = Ca, Sr, Ba).
- To investigate the superconducting properties of a solid solution (Ca1-xSrx)Pd3P.
- To explore the influence of crystal structure, specifically inversion symmetry, on superconductivity.
Main Methods:
- Synthesis of new antiperovskite phosphides M M Pd3P.
- Formation and characterization of solid solutions (Ca1-xSrx)Pd3P and (Sr1-xBax)Pd3P.
- X-ray diffraction for structural analysis and phase identification.
- Temperature-dependent electrical resistivity measurements to determine superconducting critical temperatures (Tc).
Main Results:
- Successful synthesis of CaPd3P, SrPd3P, and BaPd3P.
- Identification of three perovskite-related crystal structures in the (Ca1-xSrx)Pd3P system.
- Discovery of bulk superconductivity (Tc ≈ 3.5 K) in the centrosymmetric orthorhombic phase of (Ca1-xSrx)Pd3P for 0.17 ≤ x ≤ 0.55.
- Phase transition from centrosymmetric (Pnma) to noncentrosymmetric orthorhombic (Aba2) in CaPd3P near room temperature, with transition temperature decreasing upon Sr substitution.
- Suppression of superconductivity in noncentrosymmetric tetragonal (I41md) phases (x ≥ 0.6) and absence of superconductivity in BaPd3P.
Conclusions:
- The crystal structure and superconducting properties of M M Pd3P compounds are sensitive to cation substitution.
- Superconductivity in (Ca1-xSrx)Pd3P is strongly linked to the centrosymmetric orthorhombic crystal phase.
- The (Ca1-xSrx)Pd3P system provides a tunable platform to study the interplay between inversion symmetry and superconductivity.
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