Development of pico-Calorimeter for Ultra-Tiny Samples
Min-Nan Ou1*, Fan-Yun Chiu1,2,3, Wei-Han Tsai1, Yang-Yuan Chen1
1Institute of Physics, Academia Sinica, Taipei, Taiwan
2Department of Physics, National Taiwan University, Taipei, Taiwan
3Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan University, Taipei, Taiwan
* presenting author:MIN-NAN OU,
Topological material is a new class of quantum material that is protected by time-reversal symmetry. A couple of chalcogenide compounds Bi2Te3, Bi2Se3 and Sb2Te3 are reported as 3D topological insulators (TI). They reveal opportunities to find topological superconductivity (TSC) by band structure tuning. As an obvious example, copper intercalated CuxBi2Se3 was confirmed as a nematic superconductor by angle resolved specific heat measurement at superconducting temperature. In order to develop a calorimeter for investigating layered materials with tiny mass. Two techniques, thermal relaxation (TR) and self-heating 3 methods are employed and realized for the measurement of ultra-small samples. The thermal relaxation method (TRM) was applied in the construction of a picocalorimeter with dimensions of 70 μm × 70 μm × 300 nm on a Si3N4/Si substrate. The high reliability of the fabrication processes is confirmed by a couple of sample holders. A standard sample of a tin (purity ~99.999%) ball with diameter ~ 100 μm was placed on the pico-calorimetry by a homemade micromanipulator. The specific heat difference at TC, ∆C/γTc is ~1.69, which it agrees with the literature value of 1.6. The specific heat analysis on a flake-like layered crystal will be discussed in details. 3ω technique is an another heat capacitymeasurement method, its simple geometry of platform can minimize the thermal conductance and increase the measurement resolution. The details of this technique for the measurement of a tellurium crystal will be presented.

Keywords: topological material, layered material, superconductivity, specific heat, picocalorimeter