Structural and magnetic phase transitions in triclinic Ca sub(10)(FeAs) sub(10)(Pt sub(3)As sub(8))

• Published in: Journal of physics. Condensed matter Vol. 25; no. 12; pp. 1 - 4
• Main Authors: Sturzer, T, Friederichs, G M, Luetkens, H, Amato, A, Klauss, H-H, Johrendt, Dirk
• Format: Journal Article
• Language: English
• Published: 27.03.2013
• Subjects: Approximation; Condensed matter; Distortion; Parents; Phase transformations; Superconductors; Symmetry; Transition temperature
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/25/12/122203

We report the structural and magnetic phase transitions of triclinic Ca sub(10)(FeAs) sub(10)(Pt sub(3)As sub(8)), which is the parent compound of the 1038-type iron-arsenide superconductors. High-resolution x-ray diffraction reveals splitting of the in-plane (a, b) lattice parameters at T sub(s) [approximate] 120 K. Platinum-doping weakens the distortion and shifts the transition temperature to 80 K in Ca sub(10)(Fe sub(1-x)Pt sub(x)As) sub(10)(Pt sub(3)As sub(8)) with x = 0.03. mu SR experiments show the onset of magnetic order near T sub(s) and a broad magnetic phase transition. The structural transition involves no reduction of the space group symmetry in contrast to the other parent compounds of iron-arsenide superconductors; nevertheless the local fourfold symmetry of the FeAs-layers in Ca sub(10)(FeAs) sub(10)(Pt sub(3)As sub(8)) is broken.