کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1297207 | 1498401 | 2006 | 8 صفحه PDF | دانلود رایگان |
Optical observation, differential scanning calorimetry, thermogravimetric analysis, and differential thermogravimetric measurements have been carried out on KH2PO4 single crystals. As compared with the optical observation of crystal under polarizing microscope, the dehydration process occurred gradually over the crystal surface at temperatures above 195 °C and then the interior of the sample. The ac impedance measurements were performed as a function of both frequency and temperature. The electrical conduction and dielectric relaxation have been studied. The activation energy of migration is 1.02 eV in the temperature range between 150 and 179 °C. The conduction mechanism in this temperature range is attributed to the hopping of proton among hydrogen vacancies. At temperatures above 186 °C, a higher conductivity activation energy with 2.94 eV is obtained. In addition to the proton conduction, the migration of the heavier ions (such as potassium ion) is also suggested.
Journal: Solid State Ionics - Volume 177, Issues 33–34, 15 November 2006, Pages 2857–2864