Yttria-stabilized zirconia (YSZ) was synthesized by the spark plasma sintering process to generate pore-free, homogenous bulk samples that were then tested for thermal conductivity, which was measured by two separate methods: TPS and LFT. The TPS method was found to be better for measuring of thermal conductivity in this specific case. Using the phonon-hopping model (PHM) the authors were able to determine how grain boundaries of the bulk samples affected ...