TY - JOUR
T1 - Impedance spectroscopy and dielectric analysis in KH2PO4 single crystal
AU - Chen, R. H.
AU - Yen, Chen Chieh
AU - Shern, C. S.
AU - Fukami, T.
N1 - Funding Information:
This work was supported by the National Science Council of ROC (Project No. NSC93-2112-M-003-013 and NSC94-2112-M-003-009).
PY - 2006/11/15
Y1 - 2006/11/15
N2 - 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.
AB - 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.
KW - Dielectric properties
KW - Electrical conductivity
KW - Impedance spectroscopy
KW - KDP crystal
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U2 - 10.1016/j.ssi.2006.05.053
DO - 10.1016/j.ssi.2006.05.053
M3 - Article
AN - SCOPUS:33750490077
VL - 177
SP - 2857
EP - 2864
JO - Solid State Ionics
JF - Solid State Ionics
SN - 0167-2738
IS - 33-34
ER -