| Summary: | We have recently reported that the superconducting transition temperature of FeTe0.5Se0.5 flakes attached onto commercial Scotch tape can be enhanced by about 1-2 K due to a thermal-mismatch induced compressive strain. In this work, we further investigated the Scotch tape effect on structural variation of FeTe0.5Se0.5 and Fe1.05Te flakes by X-ray diffraction measurements. We show that for FeTe0.5Se0.5, the lattice constant c of taped flakes is elongated by about 0.5% at 15 K as compared with bulk crystal. Upon warming from 15 K, the lattice constant c of the taped flakes first levels off then displays negative thermal expansion followed by monotonic increase at temperatures above 100 K. For antiferromagnetic Fe1.05Te, the structural transition around 70 K is remarkably broadened by about 2 K. The present results demonstrate that the Scotch tape is a simple and effective tool to probe structure sensitive physical properties of layered materials.
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