Mechanical Properties of Multifunctional TiF₄ from First-Principles Calculations

Titanium tetrafluoride (TiF₄) plays a crucial role in prerestorative dentistry, the synthesis of metal fluorides and titanium silicate thin films, enhancing the photocatalytic activity of TiO₂, and hydrogen storage applications. Though TiF₄ is touted for superior catalytic activity in deflating the decomposition temperature of metal hydrides, its fundamental properties have not been studied yet. Compressibility is a vital parameter during mechanical milling and hydrogen cycling processes from solid metal hydrides to sustain its stability. Even though many high-pressure studies are available on metal hydrides, a similar study on the TiF₄ additive has not yet been conducted by either theoretical or experimental methods. In an effort to identify the compressibility of the TiF₄ catalyst, we have performed state-of-the-art density-functional-theory-based calculations for three chemical states of TiF (x = 4, 3, and 2). The mechanical strength of a material is derived from interatomic interactions, which in turn are influenced by the microstructure and bonding. The results highlight the superior structural, electronic, mechanical, and optical properties of orthorhombic TiF₄, which has octahedral columns similar to those of bone tissue material (hydroxyapatite). This article highlights the stable iono-covalent F-Ti-F bonding of the +4 state of titanium fluoride. Materials with Young's moduli close to that of bone (20-30 GPa) have been intensely searched for bone implants. TiF₄ can be used for this purpose because its average Young's modulus is 47 GPa. Our detailed analysis of charge density in TiF₄ sheds light on its unique bonding characteristics, which result in its extraordinary mechanical properties, making TiF₄ a multifunctional material not only for dental fillings but also for orthopedic and catalytic applications.