Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
Browse
3 results
Search Results
Now showing 1 - 3 of 3
Article Citation - WoS: 8Citation - Scopus: 8Fast-Firing of Potassium Sodium Niobate (knn)(Elsevier B.V., 2024) Karacasulu,L.; Karakaya,M.; Adem,U.; Sglavo,V.M.; Biesuz,M.; Vakifahmetoglu,C.Potassium sodium niobate (KNN) is one of the most promising Pb-free piezo-ceramics. In the present work, KNN was produced by fast-firing with different cooling strategies, i.e., fast and slow cooling. Dielectric, ferroelectric, and piezoelectric properties of fast-fired pellets were determined and compared with those of conventional-sintered products. Although the samples produced by fast-firing had higher density than those obtained by conventional sintering, fast-cooled samples following fast firing show relatively low electrical properties. When fast-firing was combined with slow cooling, the electrical properties, especially piezoelectric d33 values, were improved. The material subjected to fast-firing at 1120 °C using slow cooling gave the highest relative density (about 95 %) with fine grains microstructure and a d33 of 112 pC/N whereas that produced by conventional sintering resulted in d33 of 80 pC/N with a relative density of 88 % for the same dwell time (30 min). © 2024 The AuthorsConference Object Citation - Scopus: 2Fabrication of Polymer Nanofiber-Conducting Polymer Fabric and Noncontact Motion Sensing Platform(Trans Tech Publications, 2018) Mutlu, Mustafa Umut; Akın, Osman; Demir, Mustafa Muammer; Yıldız, Ümit HakanConductive polymer-electrospun polymer nanofiber network was combined to host iron oxide nanoparticles providing micrometer thick sensing interface. The sensor has fabricated as freestanding fabric exhibiting 10 to 100 KOhm base resistivity upon bias applied. The moving object has been sensed through the electrostatic interactions between fibers and object. The sensing range has been found to be 1-5 cm above the surface of fabric. By the controlled combination of conductive polymers electrospun polymer nanofibers effective device miniaturization has been provided without loss of performance. The noncontact motion sensor platform has unique flexibility and light weight holding a potential for wearable sensor technology.Article Citation - WoS: 24Citation - Scopus: 24Electrical and Dielectrical Properties of Tantalum Oxide Films Grown by Nd:yag Laser Assisted Oxidation(Elsevier Ltd., 2008) Aygün, Gülnur; Turan, RaşitTantalum pentoxide (Ta2O5) thin films (20 to 44 nm) have been grown by 1064 nm Nd:YAG laser oxidation of Ta deposited films with various thickness on Si. Fourier Transform Infrared (FTIR) spectrum, thickness distribution, dielectric and electrical properties of laser grown oxide layers have been studied. The effect of the sputtered Ta film thickness, laser beam energy density and the substrate temperature on the final Ta2O5 film structure has been determined. It is shown that the oxide layers obtained for the laser beam energy density in the range from 3.26 to 3.31 J/cm2 and the substrate temperature around 350 °C have superior properties. FTIR measurement demonstrates that the Ta2O5 layers are obtained with the laser assisted oxidation technique. Metal Oxide Semiconductor capacitors fabricated on the grown oxide layers exhibits typical Capacitance-Voltage, Conductance-Voltage and Current-Voltage characteristics. However, the density of oxide charges is found to be slightly higher than the typical values of thermally grown oxides. The conduction mechanism studied by Current-Voltage measurements of the capacitors indicated that the current flow through the oxide layer is modified Poole-Frenkel type. It is concluded that the Ta2O5 films formed by the technique of Nd:YAG laser-enhanced oxidation at relatively low substrate temperatures are potentially useful for device applications and their properties can be further improved by post oxidation annealing processes. © 2008 Elsevier B.V