1. Magnetic order tuned by Cu substitution in Fe1.1-zCuzTe.
- Author
-
Jinsheng Wen, Zhijun Xu, Guangyong Xu, Lumsden, M. D., Valdivia, P. N., Bourret-Courchesne, E., Genda Gu, Dung-Hai Lee, Tranquada, J. M., and Birgeneau, R. J.
- Subjects
- *
MAGNETIC properties of metals , *CHEMICAL systems , *COPPER , *IRON compounds , *SPIN glasses , *NEUTRON scattering , *SUPERCONDUCTORS - Abstract
We study the effects of Cu substitution in Fe1.1 Te, the nonsuperconducting parent compound of the iron-based superconductor, Fe1+yTe1-xSex, utilizing neutron scattering techniques. It is found that the structural and magnetic transitions, which occur at ∼60 K without Cu, are monotonically depressed with increasing Cu content. By 10% Cu for Fe, the structural transition is hardly detectable, and the system becomes a spin glass below 22 K, with a slightly incommensurate ordering wave vector of (0.5 -- &dgr;, 0,0.5) with S being the incommensurability of 0.02, and correlation length of 12 Â along the a axis and 9 Â along the c axis. With 4% Cu, both transition temperatures are at 41 K, though short-range incommensurate order at (0.42,0,0.5) is present at 60 K. With further cooling, the incommensurability decreases linearly with temperature down to 37 K, below which there is a first-order transition to a long-range almost-commensurate antiferromagnetic structure. A spin anisotropy gap of 4.5 meV is also observed in this compound. Our results show that the weakly magnetic Cu has a large effect on the magnetic correlations; it is suggested that this is caused by the frustration of the exchange interactions between the coupled Fe spins. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF