We have studied the structural, magnetic, and dielectric properties of the dimer-Mott insulator β′-(BEDT-TTF)2(ICl2)1-x(AuCl2)x. The AuCl2 substitution for ICl2 decreases the lattice length in the interlayer direction, leading to uniaxial chemical pressure with a negligible effect on the intralayer donor stacking. The variation of the Néel temperature as a function of x is explained on the basis of chemical pressure accompanied by anion disorder, while the dielectric response does not indicate the effect of chemical pressure. This suggests that the charge degrees of freedom are attributed to the intralayer origin such as the charge fluctuation of donor molecules induced by an electric field.
ASJC Scopus subject areas
- Physics and Astronomy(all)