Abstract-The effect on the thermal parameters of superconducting transition edge bolometers produced on a single crystalline SrTiO3 (STO) substrate with and without a CeO2 buffer layer was investigated. Metal organic deposition was used to deposit the 20 nm CeO2 buffer layer, while RF magnetron sputtering was applied to fabricate 150 nm thick superconducting YBa2Cu3O 7−δ (YBCO) thin film. The critical transition temperature for both of the YBCO films was 90 K and the transition width was ∼1.9 K. The bolometers fabricated from these samples were characterized with respect to the voltage phase and amplitude responses, and the results were compared to that of simulations conducted by applying a one-dimensional thermophysical model. It was observed that adding the buffer layer to the structure of the bolometer results in an increased response at higher modulation frequencies. Results from simulations made by fitting the thermal parameters in the model with and without an additional CeO2 layer were found to be in agreement with the experimental observations.

The liquid film motor (LFM) is a simple device which serves as a laboratory to conduct experimental research in basic theoretical studies of electrohydrodynamics (EHD). In addition the LFM can play an important role in technological applications such as micro mixers and washers. In this paper we initially performed experiments to examine the theory regarding rotation and vibration of an AC LFM. While many theoretical predictions are in agreement with our experimental data, but in the threshold of vibration there is an obvious disagreement; we showed that no threshold exists and oscillation is observed in any field value. Experimental evidence showed the existence of an elastic deformation in water before reaching the yield stress and lead us to the use of the elastic Bingham fluid model. We revised the theories using this model and investigated the behaviour of a vibrating LFM which has more applications in mixing. We applied a numerical solution to derive different phases of vibration and distinguish between elastic and plastic vibrations, the latter which could be used for mixing.

We report on the response of a monolithic high Tc transition-edge bolometer to about 3-mm-wave for the first time. The detector structure consisting of 400 nm YBa2Cu3O7−x (YBCO) film on buffered Yttria Stabilized Zirconia substrate without any coupled antenna, shows bolometric type responsivity to the 3-mm-waves radiation at its transition temperature. The YBCO thin film and Ce0.9La0.1O2 buffer layer are both fabricated by the metal-organic deposition method. The meander line pattern of the bolometer is designed for obtaining maximum absorption and responsivity possible when the polarized radiation of the source is aligned with the pattern. Meander lines are 50 micrometers wide and 1.5 mm long. We have measured amplitude and phase of the response versus modulation frequency of the detector to the linearly polarized 95 GHz source, and the detector was biased at 5 distinct temperatures at the transition corresponding to five different electrical conductivities of the YBCO film. When the meander lines of the device are parallel to the incident beam polarization, the YBCO pattern is speculated to act as a dissipative antenna resulting in higher absorption leading to high magnitude of the response as observed. The results from the measured phase of the response versus modulation frequency are also in agreement with the discussed absorbed mechanism. The absorption of the YBCO pattern is also measured to depend on the electrical conductivity of the YBCO film and our results show that there is an optimum electrical conductivity for having maximum absorption for this detector. Simulation results for this structure confirm the experiments showing that at electrical conductivity value of 1.33 × 10 5 S/m we have the maximum absorption for our device. These observations promise design of versatile THz and millimeter-wave detectors with potentials for applications in medical and security imaging.

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