In-plane uniaxial stress study of a low dimensional organic metal

We have studied the effects of in-plane uniaxial stress along both principa l axes for the quasi-two-dimensional organic conductor (BEDT-TTF)(2)KHg(SCN )(4) in terms of changes in the magnetotransport properties in high magneti c fields. This class of charge transfer organic metal salts is unique due t o the co-existence of both closed and open orbit bands at the Fermi level. We find that stress along both the alpha- and c-axis directions (in the pla ne of the quasi-two-dimensional conducting planes) destroys the low tempera ture density wave state, but in differing ways, and increases the extremal areas of the closed orbit bands. For stress along the a-axis, new low area orbits are induced, and for stress along the c-axis, the quantum oscillatio ns in the Shubnikov de Haas effect take on highly two-dimensional character . We compare our results with predictions made from band structure calculat ions for in-plane uniaxial stress. (C) 2001 Elsevier Science B.V. All right s reserved.