2008/06/30 by J. J. Hamlin, Ryan Baumbach, R. E. Baumbach +3 · 1 citation
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Magnetic and transport properties of perovskites and related materials #Rare-earth and actinide compounds #cond-mat.mtrl-sci #cond-mat.supr-con
paper · pdf · doi:10.1088/0953-8984/20/36/365220
published as J. Phys.: Condens. Matter 20, 365220 (2008) · Submitted to Journal of Physics: Condensed Matter
arxiv created 2008/07/25 · openalex publication_date 2008/08/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
Single crystals of the compound LaFePO were prepared using a flux growth technique at high temperatures. Electrical resistivity measurements reveal metallic behavior and a resistive transition to the superconducting state at a critical temperature T c ∼6.6 K. Magnetization measurements also show the onset of superconductivity near 6 K. In contrast, specific heat measurements manifest no discontinuity at T c . These results lend support to the conclusion that the superconductivity is associated with oxygen vacancies that alter the carrier concentration in a small fraction of the sample, although superconductivity characterized by an unusually small gap value cannot be ruled out. Under applied magnetic fields, T c is suppressed anisotropically for fields perpendicular and parallel to the ab -plane, suggesting that the crystalline anisotropy strongly influences the superconducting state. Preliminary high pressure measurements show that T c passes through a maximum of nearly 14 K at ∼110 kbar, demonstrating that significantly higher T c values may be achieved in the phosphorus-based oxypnictides.