Characteristics of urea under high pressure and high temperature

Fang Shuai, Ma Hong-An^†, Guo Long-Suo, Chen Liang-Chao, Wang Yao, Ding Lu-Yao, Cai Zheng-Hao, Wang Jian, Jia Xiao-Peng^‡

SEM photos of urea under different pressure, temperature, and experimental time, respectively: (a) 0.33 GPa, 300 K, 20 min; (b) 0.33 GPa, 460 K, 20 min; (c) 0.33 GPa, 460 K, 40 min; (d) 0.5 GPa, 480 K, 20 min; (e) 0.67 GPa, 500 K, 20 min; (f) 0.83 GPa, 515 K, 20 min; (g) 1 GPa, 535 K, 20 min.