title: A study of the phase transition of reheated diphenyl carbazide (DPC) by using UV spectroscopy.
abstract: Phase transition phenomenon in reheated diphenyl carbazide (DPC) is studied here using UV spectroscopy. The optical band gap for reheated DPC is obtained by measuring the optical diffused reflectance (DR) and equals to 3.55 eV. Also, the optical band gap is calculated using UV technique and equals to 3.548 eV. The absorbance of reheated DPC is studied at some selected temperatures in order to check the presence of phase transitions at 90°C and 125°C. According to the present work, the band gaps are calculated at 80°C, 110°C and 130°C and equal to 3.548 eV. But at 100°C, the optical band gap has changed to 4.139 eV. It was found that each phase of reheated DPC belongs to a certain definite crystal structure. The presence of the phase transitions are checked and confirmed by scanning electron microscopy (SEM). The structural properties and morphology of reheated diphenyl carbazide are investigated by SEM. The SEM images are taken at some selected temperatures to confirm the presence of phase transitions.
authors.affiliation: Physics Department, Faculty of Science, Cairo University, Cairo, Egypt.
authors.forename: F
authors.initials: F
authors.lastname: El-Kabbany
authors.affiliation: Physics Department, Faculty of Science, El-Fayoum University, EL-Fayoum, Egypt; Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha, Saudi Arabia.
authors.forename: S
authors.initials: S
authors.lastname: Taha
authors.affiliation: Physics Department, Faculty of Science, Cairo University, Cairo, Egypt. Electronic address: marwa_hafez@yahoo.com.
authors.forename: M
authors.initials: M
authors.lastname: Hafez
mesh_terms: D004160:Diphenylcarbazide / Q000737:chemistry*; D006358:Hot Temperature; D044367:Phase Transition; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D004160:Diphenylcarbazide
keywords: DPC; Phase transitions; UV spectroscopy