POSSIBLE TRANSITION IN D-VALINE AND L-VALINE SINGLE-CRYSTAL SAMPLES

The specific heats and temperature dependence of the x-ray powder diff ractions for the D-valine and the L-valine single crystal samples have been studied. It is found that there is a specific heat jump at 272.0 K for the D-valine samples but no jump at the same temperature for th e L-valine sample. The lambda like transition means that the co-operat ive effect is involved in this transition. There is no crystal structu re transition in the temperature range of 123-293 K for the D-valine s ample. The transition of the D-valine sample might be the possible D-L transition which is proposed by Abdus Salam.