Ziade Elbara
Primary Standards Laboratory, Sandia National Laboratories, Albuquerque, New Mexico 87123, USA.
Rev Sci Instrum. 2020 Dec 1;91(12):124901. doi: 10.1063/5.0021917.
A frequency-domain thermoreflectance (FDTR) system with a frequency range of 1 Hz to 75 MHz is presented. The wide bandwidth of pump modulation frequency enables enhanced simultaneous thermophysical property characterization of bulk and thin-film materials. The wide bandwidth FDTR system is demonstrated with simultaneous measurements of in-plane and cross-plane thermal conductivities of sapphire and muscovite mica, thickness and thermal conductivity of gold/titanium thin films, and isotropic thermal conductivity and volumetric heat capacity of lithium niobate and silicon. Thermophysical properties measured with FDTR are compared to literature values or independent measurements for verification. Finally, at low frequencies, a negligible error was achieved in the numerical integration of the heat diffusion equation with a Gauss-Legendre quadrature method solved with 400 integration points and an upper integration limit of 16w, where w is the effective pump-probe 1/e radius.
本文介绍了一种频率范围为1 Hz至75 MHz的频域热反射（FDTR）系统。泵浦调制频率的宽带宽能够增强对块状和薄膜材料的同时热物理性质表征。通过对蓝宝石和白云母的面内和面外热导率、金/钛薄膜的厚度和热导率以及铌酸锂和硅的各向同性热导率和体积热容进行同时测量，展示了宽带宽FDTR系统。将FDTR测量的热物理性质与文献值或独立测量值进行比较以进行验证。最后，在低频下，使用高斯 - 勒让德求积法在400个积分点和上限积分限为16w（其中w是有效泵浦 - 探测1/e半径）的情况下求解热扩散方程的数值积分时，实现了可忽略不计的误差。
