The electrical conduction phenomena, dielectric response and microstructure have been discussed in sintered silicon nitride ceramics at different temperature and frequencies. Microstructure and phase of the sintered s...The electrical conduction phenomena, dielectric response and microstructure have been discussed in sintered silicon nitride ceramics at different temperature and frequencies. Microstructure and phase of the sintered samples was investigated by Scanning Electron Microscope (SEM) and X-ray diffractometer (XRD). The electrical conductivity, dielectric constant and dielectric loss increases exponentially with temperature greater than 600 K. The dielectric constant and loss have been measured in the frequency range 100 Hz to 1 MHz. The a.c. conduction studies in the audio frequency range 500 Hz to 1 MHz indicates that the conduction may be due to the electronic hopping mechanism. Silicon Nitride ceramics became dense after sintering. The effect of grain size and role of phase on electrical and dielectric properties have been discussed. These types of samples can be used as a high temperature semi conducting materials for device packaging.展开更多
Aqueous binary dopant (ZrOCl2/AgI) is used in different ratio such as 1:1, 1:2 and 2:1 (w/w) for chemical doping to enhance the conductivity of synthesized Poly (o-toluidine) (POT). The doping of Poly (o-toluidine) is...Aqueous binary dopant (ZrOCl2/AgI) is used in different ratio such as 1:1, 1:2 and 2:1 (w/w) for chemical doping to enhance the conductivity of synthesized Poly (o-toluidine) (POT). The doping of Poly (o-toluidine) is carried out using tetrahydrofuran as solvent. Doped samples are characterized using various techniques such as I-V characteristics, UV-Visible spectroscopy, X-ray diffractometry (XRD), FTIR and Photoluminescence (PL) studies. A significant enhancement in DC conductivity has been observed with the introduction of binary dopant. UV-Visible study shows that optical parameters change considerably after doping. Interestingly, both direct and indirect band gaps are observed in the doped samples. XRD patterns show the semi-crystalline nature of doped Poly (o-toluidine). FTIR study shows structural modifications in functional groups with doping in POT. A Photolyminescence spectrum exhibits the emission properties of the samples.展开更多
The DC conductivity and dielectric properties of glassy Se100–xZnx 2 ≤ x ≤ 20 alloys have been investigated in the temperature range 303 - 487 K with frequency range 100 Hz – 1 MHz. It is observed that DC conducti...The DC conductivity and dielectric properties of glassy Se100–xZnx 2 ≤ x ≤ 20 alloys have been investigated in the temperature range 303 - 487 K with frequency range 100 Hz – 1 MHz. It is observed that DC conductivity decreases and the activation energy increases with Zn content in Se-Zn system. Dielectric dispersion is observed when Zn incorporated in Se-Zn glassy system. The results are explained on the basis of DC conduction mechanism and dipolar-type dielectric dispersion.展开更多
文摘The electrical conduction phenomena, dielectric response and microstructure have been discussed in sintered silicon nitride ceramics at different temperature and frequencies. Microstructure and phase of the sintered samples was investigated by Scanning Electron Microscope (SEM) and X-ray diffractometer (XRD). The electrical conductivity, dielectric constant and dielectric loss increases exponentially with temperature greater than 600 K. The dielectric constant and loss have been measured in the frequency range 100 Hz to 1 MHz. The a.c. conduction studies in the audio frequency range 500 Hz to 1 MHz indicates that the conduction may be due to the electronic hopping mechanism. Silicon Nitride ceramics became dense after sintering. The effect of grain size and role of phase on electrical and dielectric properties have been discussed. These types of samples can be used as a high temperature semi conducting materials for device packaging.
文摘Aqueous binary dopant (ZrOCl2/AgI) is used in different ratio such as 1:1, 1:2 and 2:1 (w/w) for chemical doping to enhance the conductivity of synthesized Poly (o-toluidine) (POT). The doping of Poly (o-toluidine) is carried out using tetrahydrofuran as solvent. Doped samples are characterized using various techniques such as I-V characteristics, UV-Visible spectroscopy, X-ray diffractometry (XRD), FTIR and Photoluminescence (PL) studies. A significant enhancement in DC conductivity has been observed with the introduction of binary dopant. UV-Visible study shows that optical parameters change considerably after doping. Interestingly, both direct and indirect band gaps are observed in the doped samples. XRD patterns show the semi-crystalline nature of doped Poly (o-toluidine). FTIR study shows structural modifications in functional groups with doping in POT. A Photolyminescence spectrum exhibits the emission properties of the samples.
文摘The DC conductivity and dielectric properties of glassy Se100–xZnx 2 ≤ x ≤ 20 alloys have been investigated in the temperature range 303 - 487 K with frequency range 100 Hz – 1 MHz. It is observed that DC conductivity decreases and the activation energy increases with Zn content in Se-Zn system. Dielectric dispersion is observed when Zn incorporated in Se-Zn glassy system. The results are explained on the basis of DC conduction mechanism and dipolar-type dielectric dispersion.
