Thermal parameters of MgSO4·7H2O and NiSO4·7H2O crystals added with urea and thiourea

✍ Scribed by C.K. Mahadevan

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 130 KB
• Volume: 403
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2008.03.027

✦ Synopsis

Pure and impurity-added (with urea and thiourea) MgSO 4 Á 7H 2 O and NiSO 4 Á 7H 2 O single crystals were grown by the free-evaporation method from aqueous solutions. Density was measured by the flotation method. X-ray diffraction data were collected for powder samples and used for the estimation of thermal parameters like Debye-Waller factor, mean-square amplitude of vibration, Debye temperature and Debye frequency. The thermal parameters do not vary in a particular order with respect to impurity concentration, which could be attributed to the random disturbance created by the impurity molecules in the hydrogen-bonding system of the MgSO 4 Á 7H 2 O and NiSO 4 Á 7H 2 O lattices.