Incommensurate Phase Transition in 4,4'-Dichlorodiphenyl Sulfone

Abstract

The structural phase transition in a 4,4 ′ -dichlorodiphenyl sulfone single crystal was investigated by means of X-ray diffraction. It has been found that the crystal shows the normal-incommensurate phase transition at 150 K with the modulation wavevector q = a * ±(1/5+δ) b * , where a * and b * represent the reciprocal lattice vectors in the normal phase and δ represents the small misfit parameter in the incommensurate phase. No lock-in phase transition was confirmed within the temperature range 20-150 K.