Manifestation of intermediate phase in Cu doped Si-Te glasses

• Published in: Journal of non-crystalline solids 2020-03, Vol.531, p.119863, Article 119863
• Main Authors: Roy, Diptoshi, Tanujit, B., B, Jagannatha K., Varma, G. Sreevidya, Asokan, S., Das, Chandasree
• Format: Article
• Language: English
• Subjects: Boolchand intermediate phase; Chalcogenide glass; Chemical threshold
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2019.119863

•The XRD of crystallized Si-Te-Cu system reveals that the phases which have crystallized are: Hexagonal Te; tetragonal Cu3Te2; hexagonal Si2Te3 and Si1Te2.•Tg, Tcand ∆T with composition reveals that the glasses in the span of 2 ≤ x ≤ 6 have better network connectivity and are thermally more stable.•The study of ΔHNR distinctly stipulates the existence of 'Boolchand's intermediate phase in 2 ≤ x ≤ 6.•The dip in Tgand Tcindicates the manifestation of chemical threshold at x = 9. Alternating differential scanning calorimetry (ADSC) analysis has been carried out on bulk Si15Te85-xCux (1 ≤ x ≤ 10) glasses to examine the thermal properties of the glassy samples in detail. The investigations on the compositional dependence of ΔHNR (non- reversing enthalpy) manifests a trough between the composition 2 ≤ x ≤ 6 which stands as the basis of the presence of Boolchand's Intermediate phase in that range. Additionally, anomalous behavior has been observed at the compositional dependence of various thermal parameters at x = 9, which stipulates the appearance of chemical threshold at the stated composition. Annealed bulk samples have been exposed to XRD studies to discern the type of formed crystalline phases. The study has reported the manifestation of Te, Si1Te2, Si2Te3, Cu3Te2 phases.