Conductivity and incommensurate antiferromagnetism of Fe_1.02Se_0.10Te_0.90 under pressure

¹ Department of Physics, University of Virginia, 382 McCormick Road - Charlottesville, VA 22904, USA
² The Institute for Solid State Physics, University of Tokyo - Kashiwa, Chiba 277-8581, Japan
³ Department of Applied Physics, University of Tokyo - 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
⁴ NIST Center for Neutron Research, National Institute of Standards and Technology - Gaithersburg, MD 20899, USA
⁵ Department of Materials Science and Engineering, University of Maryland - College Park, MD 20742, USA
⁶ Advanced Institute for Materials Research, Tohoku University - Sendai 980-8577, Japan

^a katayama@mcr.nuap.nagoya-u.ac.jp

Received: 9 January 2012
Accepted: 11 April 2012

Abstract

By performing resistivity, bulk susceptibility and neutron diffraction on single crystals of Fe_1.02Se_0.10Te_0.90 under pressure, we show that an external pressure can enhance both conductivity and magnetism simultaneously. Surprisingly, the pressure-induced magnetic order is nearly three-dimensional, and incommensurate along both the c-axis and the a-axis, which is accompanied by a structural phase separation. Our powder neutron diffraction data show that the Fe(Se, Te)₄ tetrahedron becomes more regular under pressure, which is consistent with the enhancement of the metallicity but is counterintuitive to the three-dimensional magnetic order.