| Summary: | 碩士 === 國立交通大學 === 電子物理系所 === 105 === RuO2 is a metal oxide and has good electrical conductivity and thermal stability. From the previous RuO2 electrical measurement result, the conductance fluctuations would increase as the temperature decrease. We think that the conductance fluctuation result from mobile defect in the two-level-systems (TLSs). In this thesis, we fabricate ruthenium dioxide with different thickness films by magnetron sputtering and we take advantage of X-ray diffraction to confirm the existence of tetragonal rutile structure. From the electrical measurement, we found the rise of the resistance at low temperature (0.3 K < T < 10 K) and reveal strong lnT increment. From two or three dimensional weak localization and electron-electron interaction, we found the fitting value from conductance correction is considerately smaller than we had measured. We think that the existence of the Kondo effect dominates lnT dependence and it origins from the scattering between electron and two-level-systems.
In order to study two-level-systems inside RuO2, we concentrated on low frequency noise measurement in high temperature region. We use five probes method to measure noise and found that our power spectrum density is proportional to in Hooge formula. Additionally, we found the noise magnitude would decrease in oxygen annealing, while the noise signal would increase in Argon annealing. We think the existence of oxygen vacancies result from the argon annealing. In this thesis, we mainly use thermal activation model to explain high temperature noise and the relation between TLSs energy distribution.
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