Barium titanate is an inorganic chemical compound which is available in a white powder form. It is a ferroelectric ceramic chemical compound with piezoelectric characteristics.

Identification

CAS reference number: 12047-27-7

PubChem Substance ID: 24870427

ChemSpider Reference Number: 10605734

MDL number: MFCD00003447

EC Number: 234-975-0

HS Code: 2841 90 85

Chemical Formula for Barium titanate

The chemical formula for Barium titanate is BaTiO₃.

Production of Barium titanate

Barium titanate is synthesized by heating titanium dioxide and barium carbonate.  This reaction takes place through liquid phase sintering. Single crystals of Barium titanate can be produced at around 1100 °C from molten potassium fluoride.

Picture 1 – Barium titanate
Source – thermograde.com

Properties of Barium titanate

The physical and chemical properties of Barium titanate are listed below:

Appearance

This inorganic compound is available as transparent large crystals and as a white powder.

Molar Mass

The molar mass of this substance is 233.192 g/mol.

Density

The density of this chemical compound is 6.02 g/cm³ in solid state and 6.08 g/mL in liquid state at 25 °C.

Melting Point

The melting point for this substance is 1625 °C.

Hardness

Barium titanate has a hardness of 5 in Mohs scale.

Photorefractivity

Barium titanate shows photorefractive properties.

Piezoelectricity

The chemical compound has piezoelectric properties.

Solubility

Barium titanate is insoluble in water and alkalis. It is however, soluble in several acids such as hydrochloric acid, hydrofluoric acid and sulfuric acid. The compound can dissolve completely in concentrated hydrofluoric acid and sulfuric acid.

Structure of Barium titanate

Barium titanate is available in powder or crystal forms which have a perovskite structure. The structure of solid Barium titanate may vary with temperature. They can exist in five different phases, from low temperature to high temperature: rhombohedral, orthorhombic, tetragonal, cubic and hexagonal. Ferroelectric properties are displayed by all the phases except the cubic phase. The cubic phase has octahedral TiO₆ centers which defines a cube with Ti-O-Ti edges and Ti vertices.

Uses of Barium titanate

Barium titanate has many uses:

• Barium titanate can be used as an electrical insulator in its purest form.
• The compound is used in capacitors as a dielectric ceramic material.
• It is also be used as a piezoelectric material in microphones and other transducers.
• Barium titanate can be doped with certain amounts of other metals like yttrium, scandium and samarium to make it a semiconducting material. As a semiconductor, Barium titanate shows PTCR properties in polycrystalline form.
• The Curie temperature for Barium titanate is 120 °C and spontaneous polarization at room temperature is about 0.15 C/m². At Curie temperature, Barium titanate shows an increased resistivity which can vary in magnitude. In this temperature, Barium titanate may change its phase from tetrahedral to cubic.
• Single crystals of this compound can show NTCR properties. Polycrystalline forms of the compound shows positive temperature coefficient. Due to this, it is used in preparing self-regulating electric heating systems and thermistors.
• Barium titanate crystals are also used in nonlinear optics as it has high beam-coupling gain and can operate at near-infrared and visible wavelengths.
• Barium titanate has got the highest reflectivity for materials used in SPPC applications. It is used in continuous four-wave mixing having milliwatt-range optical power.
• Barium titanate can be used in photorefractive applications.
• In frequencies over 40 GHz, thin films of this compound show electro-optic modulating properties.
• The ferroelectric and pyroelectric properties of this substance are used to manufacture some varieties of un-cooled sensors used in thermal cameras.
• Barium titanate powder of high purity is used to manufacture barium titanate capacitor energy storage systems that are used in electric vehicles.

Barium titanate MSDS

Health Hazards

Exposure to Barium titanate can cause serious harm to human health:

Skin contact: The compound might produce irritation if it comes in contact with the skin.

Eye contact: Exposure of the eyes to this chemical can cause irritation of the eyes.

Ingestion: Ingestion of this chemical can cause irritating sensations in the digestive tract.

Inhalation: Irritation of the respiratory tract is caused by inhalation.

First Aid Measures

Eyes: In case of an eye exposure, the eyes should be flushed with lots of water for a minimum of 15 minutes. The eyelids should be lifted occasionally while the eyes are sprinkled with water. A doctor should be consulted after that.

Skin: In case of a skin contact, a dermatologist should be contacted immediately. The contaminated clothing should be removed immediately and the clothes and shoes should be washed properly before being reused. The infected skin areas should be washed with running water for a minimum of 15 minutes.

Ingestion: In case of ingestion, the victim should be given proper medical attention. Vomiting should not be induced under any circumstances. Nothing ever should be given orally to an unconscious individual. If the victim is alert and conscious, the mouth should be rinsed properly and a few cups of water or milk should be given to the individual.

Inhalation: The victim should be immediately removed to an area of fresh air. Artificial respiration should be used if the victim is not breathing properly. Oxygen supply should be administered if breathing is still difficult. Medical help is needed to ensure the victim’s safety.

Fire Fighting Measures

During a fire break-out, highly toxic and irritating gases may be produced by combustion and thermal decomposition. Hence while firefighting, special MSHA/NIOSH (approved or equivalent) self-contained breathing apparatus having pressure-demand oxygen masks should be used along with full protective gear.

Fire Extinguishing Media: Appropriate fire extinguishing media must be used to put off fire. Water spray, carbon dioxide, foam or dry chemical should be used to handle fire.

Accidental Release Measures

The chemical spills should be cleaned up immediately. Proper protective gear should be used while doing so. The chemicals should be absorbed or swept up properly and placed in a dry and closed container before being disposed. Dusty environments should be avoided and proper ventilation should be provided at the storage section.

Handling of Barium titanate

The storage sections should be provided with adequate ventilation. Accumulation of dust should be avoided. The containers storing the chemical should be tightly closed. Exposure to the skin, eyes, clothing or inhalation and ingestion should be avoided at all costs.

Storage of Barium titanate

The containers storing the chemical should be tightly closed when they are not in use. They should be kept in a dry and well-ventilated area and kept away from incompatible materials.

Personal Protection

Adequate protection should be used while dealing with this chemical. Protection gear should include the following:

MSHA/NIOSH (approved or equivalent) self-contained breathing apparatus with pressure-demand oxygen masks.

Safety goggles or protective eyewear approved by OSHA is to be used for protection of eyes.

Protective gloves and clothing is to be used to avoid skin exposure.

Engineering Controls

The areas used for storing this chemical should be provided with a safety shower and an eyewash facility. There should also be adequate general and exhaust ventilation to control exposure of airborne materials.

Barium titanate is a chemical compound with many uses in various industries and other fields.

References
1. http://www.azom.com/article.aspx?ArticleID=2280
2. http://en.wikipedia.org/wiki/Barium_titanate
3. https://fscimage.fishersci.com/msds/58263.htm
4. https://www.sigmaaldrich.com/catalog/product/aldrich/208108?lang=en®ion=IN