HIGH-OXYGEN-PRESSURE SYNTHESIS, STRUCTURE AND PROPERTIES OF THE INFINITE-CHAIN COMPOUND SR0.73CUO2

A new low-dimensional compound has been synthesized at high oxygen pre ssure P-O2 = 2000 bar. X-ray single crystal structure analysis shows t hat Sr0.73CuO2 has a semi-incommensurate structure consisting of one-d imensional corrugated edge-sharing CuO2 chains alternating with Sr pla nes. From susceptibility measurements this compound is found to have a n antiferromagnetic exchange coupling with a Curie-Weiss temperature o f 135 K. A sharp magnetic transition occurs at 10 K which progressivel y disappears at applied magnetic fields larger than 1 T. While not yet understood this transition could originate from a structural instabil ity.