High pressure study of BaFe2As2—the role of hydrostaticity and uniaxial stress

• Published in: Journal of physics. Condensed matter Vol. 22; no. 5; p. 052201
• Main Authors: Duncan, W J, Welzel, O P, Harrison, C, Wang, X F, Chen, X H, Grosche, F M, Niklowitz, P G
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 10.02.2010; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Physics; Pressure effects; Superconductivity; Transition temperature variations; Phase diagrams; Electrical conductivity; Pressure effects; Superconducting transitions; Superconductivity; High pressure; Monocrystals; Uniaxial stress; Iron based arsenide; Barium Iron Arsenides Mixed; Bridgman method; Crystal growth from melts; Spin density waves
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/22/5/052201

We investigate the evolution of the electrical resistivity of BaFe(2)As(2) single crystals with pressure. The samples used were from the same batch, grown using a self-flux method, and showed properties that were highly reproducible. Samples were pressurized using three different pressure media: pentane-isopentane (in a piston-cylinder cell), Daphne oil (in an alumina anvil cell) and steatite (in a Bridgman cell). Each pressure medium has its own intrinsic level of hydrostaticity, which dramatically affects the phase diagram. An increasing uniaxial pressure component in this system quickly reduces the spin density wave order and favours the appearance of superconductivity, which is similar to what is seen in SrFe(2)As(2).