Simultaneous measurement of thermal conductivity and heat capacity across diverse materials using the square-pulsed source (SPS) technique

• DOI: 10.1016/j.icheatmasstransfer.2024.107849
• Publication Date: 2024-07-27T19:14:30Z
• Authors: Tao Chen; Shangzhi Song; Yang Shen; Kexin Zhang; Puqing Jiang
• Keywords: FOS: Physical sciences; Physics - Applied Physics; Applied Physics (physics.app-ph); 02 engineering and technology; 0210 nano-technology

State-of-the-art techniques like dual-frequency Time-Domain Thermoreflectance (TDTR) and Frequency-Domain Thermoreflectance (FDTR) offer superb capability for simultaneous measurements of thermal conductivity and heat capacity with a spatial resolution on the order of 10 μm. However, their applicability is limited to highly conductive materials with an in-plane thermal conductivity exceeding 10 W/(m*K). In this paper, we introduce the Square-Pulsed Source (SPS) technique, offering a novel approach to concurrently measure thermal conductivity and heat capacity with a 10 μm spatial resolution, while significantly extending the measurable thermal conductivity range to an unprecedented low of 0.1 W/(m*K), offering enhanced versatility. To demonstrate and validate its efficacy, we conducted measurements on various standard materials--PMMA, silica, sapphire, silicon, and diamond--spanning a wide thermal conductivity range from 0.1 to 2000 W/(m*K). The obtained results exhibit remarkable agreement with literature values, with a typical measurement uncertainty of less than 10% across the entire thermal conductivity range. By providing a unique capability to characterize both highly and lowly conductive materials with micron-scale spatial resolution, the SPS method opens new avenues for understanding and engineering thermal properties across diverse applications.