Epitaxial FeSe 0.5 Te 0.5 thin ﬁlms with different thickness were grown by pulsed laser ablation deposition on different substrates. High purity phase and fully epitaxial growth were obtained. By varying the ﬁlm thickness, superconducting transition temperatures up to 21 K were observed, signiﬁcantly larger than the bulk value 16.2 K. Structural analyses indicated that the c-axis is smaller than the bulk value but it is almost independent of the ﬁlm thickness and the a-axis changes signiﬁcantly with the ﬁlm thickness and is linearly related to the Tc . The latter result indicates the important role of the compressive strain in enhancing Tc . Tc is also related to both the Fe–(Se,Te) bond length and angle, suggesting the possibility of further enhancement.
File in questo prodotto:
Non ci sono file associati a questo prodotto.