Strain analysis of thermoelectric materials using high-resolution synchrotron X-ray diffraction data

Nakasawa, Hayato*; Shobu, Takahisa  ; Tominaga, Aki; Fujii, Masashi*; Matsumoto, Hironari*; Matsuda, Michiko*; Shimada, Takeshi*; Trivedi, V.*; Tachibana, Makoto*; Tsujii, Naohito*; Mori, Takao*

A compressive strength limit is one of critical parameters for thermoelectric materials. In this study, we synthesized a single crystal of Yb-filled Co-Sb-based skutterudite. We assessed the compressive pressure dependence of internal strain using high-resolution synchrotron radiation X-rays at SPring-8. The prepared single crystal was identified as Yb0.148Co4Sb12.54, with a lattice parameter of 0.90504 nm. Compressive testing was performed until the sample fractured, revealing a compressive strength limit of 591.3 MPa. The stress-strain curve exhibited a nearly constant slope for strains exceeding 0.07 %, leading to an estimated Young's modulus of 154.6 GPa.