Implications of Laser‐Induced Polymorphism Transformations in Bismuth(III) Vanadate Raman Spectroscopy Characterization

ABSTRACT This study addresses the challenge of distinguishing between ms‐BiVO 4 (monoclinic scheelite) and ts‐BiVO 4 (tetragonal scheelite) using Raman spectroscopy as a complementary technique to powder X‐ray diffraction (XRD). The difficulty arises particularly from their similar XRD patterns and the lack of spatial resolution inherent in conventional powder XRD methods. Bismuth(III) vanadate (BiVO 4 ) is an important technological material used in yellow pigments, as well as in solar energy conversion and photocatalytic applications. Its polymorphic nature depends on the synthetic method employed, which affects its performance. Therefore, an accurate identification of the crystalline phases present in a sample is crucial. We demonstrate that the identification of the BiVO 4 crystalline phases via Raman spectroscopy is critically dependent on laser power, which may induce an in situ polymorphic transition that can lead to misinterpretations regarding the predominant phase present in the sample. Furthermore, our findings demonstrate the efficacy of confocal Raman spectroscopy in resolving the spatial distribution of ms‐BiVO 4 and ts‐BiVO 4 within the same sample, providing an important approach for accurately distinguishing between these crystalline phases.