Unveiling the crystallographic origin of mechanochemically induced monoclinic to triclinic phase transformation in WO3. Issue 8 (10th February 2021)

• Record Type: Journal Article
• Authors: Bandi, Suresh; Srivastav, Ajeet K.
• Is Part Of: CrystEngComm. Volume 23:Issue 8(2021)
• Page Start: 1821
• Page End: 1827
• Publication Date: 2021-02-10
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/d0ce01813a
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : This study reports the anomalously stabilized low-temperature triclinic phase (δ-WO3 ) during high energy ball milling (HEBM) of the monoclinic γ-WO3 phase. Abstract : This study reports the anomalously stabilized low-temperature triclinic phase (δ-WO3 ) during high energy ball milling (HEBM) of the monoclinic γ-WO3 phase. The transformation evidenced unit cell contraction with distorted structural parameters resulted in a lower symmetry phase. The phase transformation was understood to be HEBM-induced pressure/compression involved atomic displacement and octahedral tilting-driven polymorphic transition. The major distortion/cooperative octahedral tilting occurred on the (020) plane of γ-WO3 parallel to the b axis. The crystallographic origin of such distortions and unit cell compression mechanisms are explained further. The obtained δ-WO3 phase was stable at room temperature owing to its nanocrystalline structure (11 ± 6 nm) that limits reversible and forward transformations of δ-WO3 → γ-WO3 and γ-WO3 → ε-WO3, respectively.