About Titanates

Aluminum Titanate

Titanates are compounds containing titanium, oxygen, and at least one additional metallic element. Some of the most common titanates are strontium titanate, barium titanate, calcium titanate, and dysprosium titanate.

Strontium titanate, at room temperature, is a centrosymmetric paraelectric material with a perovskite structure. However, at low temperatures it nears a ferroelectric phase transition with a very large dielectric constant, but remains paraelectric down to the lowest temperatures measured. It was long thought to be an entirely artificial material until 1982 when its natural counterpart tausonite was recognized. Tausonite remains an extremely rare mineral in nature, occurring as extremely small crystals. Strontium titanate’s most important application has been in its synthesized form; it is occasionally used as a diamond alternative, in precision optics, in varistors, and in advanced ceramics. Strontium titanate is both much denser and much softer than diamond. Its crystal system is cubic and its refractive index is nearly identical to that of diamond, but the dispersion (the optical property responsible for the "fire" of cut gem stones) of strontium titanate is over four times higher, resulting in an excess of fire when compared to diamond.

Synthetic strontium titanate is usually transparent and colorless, but it can be doped with certain rare earth or transition metals to produce red, yellow, brown, and blue hues. Natural tausonite is usually translucent to opaque, in shades of reddish brown, dark red, or grey. Both have an diamond-like luster. Synthetic strontium titanate has a very large dielectric constant and is used in high-voltage capacitors. At 0.35 K strontium titanate is superconductive and was the first insulator and oxide in which this property was studied. At temperatures lower than 105 K, its cubic structure transforms to tetragonal, making it an excellent substrate for epitaxial growth of high-temperature superconductors and many oxide-based thin films. Strontium titanate can be used as optical windows and high-quality sputtering targets.

Strontium titanate is also periodically manufactured for use in jewelry. It is one of the most costly of diamond alternatives, and due to its rarity collectors may pay a premium for large specimens. As a diamond substitute, strontium titanate is most deceptive when mingled with melée and when it is used as the base material for a composite or doublet stone. Under the microscope, gemologists distinguish strontium titanate from diamond by the former's softness and excess dispersion, and occasional gas bubbles which are remnants of synthesis. Doublets can be detected by a join line at the girdle and flattened air bubbles or glue visible within the stone at the point of bonding.

Barium titanate is an oxide composed of barium and titanium. Barium titanate appears as white powder or transparent crystals. It is insoluble in water, but will dissolve in concentrated sulfuric acid. It is a ferroelectric ceramic material, with a photorefractive effect and piezoelectric properties. Solid barium titanate has five phases: hexagonal, cubic, tetragonal, orthorhombic, and rhombohedral crystal structure. All of the crystal structures with the exception of the cubic exhibit the ferroelectric effect. Barioperovskite is a very rare natural analogue of barium titanate, found as micro-inclusions in benitoite. Adding of inclusions of barium titanate to tin has been shown to create material with a higher visco-elastic stiffness than that of diamonds.

Barium titanate can be manufactured by liquid phase sintering of barium carbonate and titanium dioxide, sometimes with other materials for doping. Barium titanate is often mixed with strontium titanate and is used as a dielectric material for ceramic capacitors and as a piezoelectric material for microphones and other transducers. Polycrystalline barium titanate displays positive temperature coefficient, making it a useful material for thermostats and self-regulating electric heating systems. High purity barium titanate powder is reported to be a key component of new barium titanate capacitor-based alternative energy storage systems for use in electric vehicles.

Barium titanate crystals can be used in nonlinear optics. The material has high beam-coupling gain, and can be operated at visible and near-infrared wavelengths. It has the highest reflectivity of the materials used for self-pumped phase conjugation applications. Thin films of barium titanate display electro-optic modulation to frequencies over 40 GHz. The pyro-electric and ferroelectric properties of barium titanate are exploited in some types of uncooled sensors for thermal cameras.

Calcium titanate is a chemical compound and a mineral known as perovskite, named after Russian mineralogist, L. A. Perovski (1792-1856). Calcium titanate can aid in the integration of biomaterials such as bone implants in hip replacement surgery. It has low dielectric loss, especially at microwave frequencies and is therefore used as dielectric material in ceramic capacitors.

Dysprosium titanate is a ceramic titanate with pyrochlore structure and is a "spin ice" material. In 2009, dysprosium titanate was observed to have quasi-particles resembling magnetic monopoles at low temperature and high magnetic field. Dysprosium titanate is also being investigated as a new material for nuclear reactor control rods.

Recent Research & Development for Titanates

New quercetin-coated titanate nanotubes and their radiosensitization effect on human bladder cancer., Alban, Luisa, Monteiro Wesley Formentin, Diz Fernando Mendonça, Miranda Gabriela Messias, Scheid Carolina Majolo, Zotti Eduardo Rosa, Morrone Fernanda Bueno, and Ligabue Rosane , Mater Sci Eng C Mater Biol Appl, 2020 May, Volume 110, p.110662, (2020)

Phase Evolution, Filler-Matrix Interactions, and Piezoelectric Properties in Lead Zirconate Titanate (PZT)-Filled Polymer-Derived Ceramics (PDCs)., Eichhorn, Franziska, Kellermann Simone, Betke Ulf, and Fey Tobias , Materials (Basel), 2020 Mar 26, Volume 13, Issue 7, (2020)

Synergistic effect of nitrogen-doping and graphene quantum dot coupling for high-efficiency hydrogen production based on titanate nanotubes., Zhang, Lin, Xue Jiayan, Long Lizhen, Yang Li, Liu Fuchi, Lv Fengzhen, Kong Wenjie, and Liu Jun , Nanotechnology, 2020 Mar 13, Volume 31, Issue 11, p.115705, (2020)

Impact of Fe, Mn co-doping in titanate nanowires photocatalytic performance for emergent organic pollutants removal., Barrocas, B, Chiavassa L D., M Oliveira Conceição, and Monteiro O C. , Chemosphere, 2020 Jul, Volume 250, p.126240, (2020)

Energy Conversion Capacity of Barium Zirconate Titanate., Binhayeeniyi, Nawal, Sukwisute Pisan, Nawae Safitree, and Muensit Nantakan , Materials (Basel), 2020 Jan 09, Volume 13, Issue 2, (2020)

Interface-Dominated Time-Dependent Behavior of Poled Poly(Vinylidene Fluoride-Trifluoroethylene)/Barium Titanate Composites., Vacche, Sara Dalle, Damjanovic Dragan, Michaud Véronique, and Leterrier Yves , Materials (Basel), 2020 Jan 04, Volume 13, Issue 1, (2020)

Preconcentration of Lead in Blood and Urine Samples Among Bladder Cancer Patients Using Mesoporous Strontium Titanate Nanoparticles., Mortada, Wael I., and Abdelghany Amr M. , Biol Trace Elem Res, 2020 Jan, Volume 193, Issue 1, p.100-110, (2020)

Electric-Field-Induced Phase Transformation and Frequency-Dependent Behavior of Bismuth Sodium Titanate-Barium Titanate., Lee, Kai-Yang, Shi Xi, Kumar Nitish, Hoffman Mark, Etter Martin, Checchia Stefano, Winter Jens, da Silva Lucas Lemos, Seifert Daniela, and Hinterstein Manuel , Materials (Basel), 2020 Feb 27, Volume 13, Issue 5, (2020)

A type-II interband alignment heterojunction architecture of cobalt titanate integrated UiO-66-NH: A visible light mediated photocatalytic approach directed towards Norfloxacin degradation and green energy (Hydrogen) evolution., Subudhi, Satyabrata, Paramanik Lekha, Sultana Sabiha, Mansingh Sriram, Mohapatra Priyabrat, and Parida Kulamani , J Colloid Interface Sci, 2020 Feb 13, Volume 568, p.89-105, (2020)

Barium Titanate Nanoparticles Sensitise Treatment-Resistant Breast Cancer Cells to the Antitumor Action of Tumour-Treating Fields., Yoon, Yi Na, Lee Dae-Sik, Park Hyung Ju, and Kim Jae-Sung , Sci Rep, 2020 Feb 13, Volume 10, Issue 1, p.2560, (2020)

Characterization data of titanate compounds synthesized using hydrothermal method at various temperature., Razali, Mohd Hasmizam, Ismail Nur Arifah, Osman Uwaisulqarni M., Rozaini Mohd Zul Helmi, and Yusoff Mahani , Data Brief, 2020 Feb, Volume 28, p.104992, (2020)

Cone-shaped titanate immobilized on polyacrylonitrile nanofibers: hierarchical architecture for effective photocatalytic activity., Zhu, Mingyue, Qin Chuanxiang, Wang Jian-Jun, Sun Jun, and Dai Lixing , Dalton Trans, 2020 Apr 07, Volume 49, Issue 13, p.4067-4077, (2020)

Strong Orbital Polarization in a Cobaltate-Titanate Oxide Heterostructure., Lee, Sangjae, Lee Alex Taekyung, Georgescu Alexandru B., Fabbris Gilberto, Han Myung-Geun, Zhu Yimei, Freeland John W., Disa Ankit S., Jia Yichen, Dean Mark P. M., et al. , Phys Rev Lett, 2019 Sep 13, Volume 123, Issue 11, p.117201, (2019)

Titanium dioxide nanoparticles-based colorimetric sensors for determination of hydrogen peroxide and triacetone triperoxide (TATP)., Gökdere, Bahar, Üzer Ayşem, Durmazel Selen, Erçağ Erol, and Apak Reşat , Talanta, 2019 Sep 01, Volume 202, p.402-410, (2019)

Tin titanate-the hunt for a new ferroelectric perovskite., Gardner, J, Thakre Atul, Kumar Ashok, and Scott J F. , Rep Prog Phys, 2019 Sep, Volume 82, Issue 9, p.092501, (2019)