Comparative Study Of 3? Method And Suspended Microdevice Method Of Thermal Conductivity Measurement Of One-dimensional Nanostructures

3? method and suspended microdevice method has been widely used in the one-dimensional nanostructure thermal conductivity measurement. But there is no unitied criterion for the accuracy of 3? method and suspended microdevice method. It can be regarded as the criterion of 3? method and suspended microdevice method for measuring the thermal conductivity of the same one-dimensional nanostructure.This thesis established an 3? method thermal conductivity measurement platform and calibrated the test platform respectively using bulk material Si and platinum wire of diameter 19?m. The measured bulk Si is the same sample with CUHK. The difference of thermal conductivity of Si and CUHK is mostly within 10%, indicating that the 3? test circuit is correct. At room temperature 300K, the thermal conductivity of platinum wire is 67.5 W/mK. The diffenence is 5.7% compared with the accepted value 71.6 W/mK. The overall relative uncertainty of thermal conductivity is 7.19%, indicationg that the data process is correct for measuring the one-dimensional nanostructure using 3? method.Study three couples of single Bi2Se3 nanoribbon using 3? method and suspended microdevice method. Results show that 3? method is greater than suspended microdevice method. But it cannot be accouted for the large contact resistance. The specific reason needs to be further studied.Experiments are carried out to study the effects of the number of radiation shield on the temperatures of the heat source/sink and the substrate in the temperature range of 20?360 K. Results show that, when heating current is not applied, the temperature difference between the heat source/sink and substrate can be neglected when three radiation shields are used. The maximum difference temperature between the heat source/sink and substrate is 0.4 K using two radiation shields. However, when only one radiation shield is used, the temperature difference can be as large as 11.8 K, which can caused large error in measurement. Therefore, at least two radiation shields should be used to minimize the radiation effect.