Suppression of the charge-density-wave state in Sr10 Ca4 Cu24 o41 by external pressure

Abstract

The influence of external pressure on the charge-density-wave (CDW) ground state of the quasi-one-dimensional two-leg ladder compound Sr10Ca4Cu24o41 has been studied by optical reflectivity measurements as a function of temperature (10-300 K) and pressure P (0.3-4.3 GPa) over the spectral range 580-6000 cm1. With increasing pressure the CDW transition temperature TCDW decreases with the linear pressure coefficient ≈-70 K/GPa, and above ≈3 GPa the CDW phase is suppressed at all temperatures. This behavior is similar to that in compounds Sr14-xCaxCu24o41 with increasing Ca content x at ambient pressure, with the simple scaling x≈3×P(GPa). The size of the CDW gap decreases with increasing pressure, whereas the dimensionality of the high-temperature insulating phase in Sr10Ca4Cu24o41 within the ladder plane is hardly affected by external pressure. © 2014 American Physical Society.