Bismuth silicon oxide is a solid inorganic compound of

bismuth Bismuth is a chemical element with the Symbol (chemistry), symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental ...

silicon Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic tab ...

and

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

. Its most common

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...

is Bi₁₂SiO₂₀, though other compositions are also known. It occurs naturally as the mineral sillénite and can be produced synthetically, by heating a mixture of bismuth and silicon oxides. Centimeter-sized single crystals of Bi₁₂SiO₂₀ can be grown by the Czochralski process from the molten phase. They exhibit

piezoelectric Piezoelectricity (, ) is the electric charge that accumulates in certain solid materials—such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins—in response to applied Stress (mechanics), mechanical s ...

electro-optic Electro–optics is a branch of electrical engineering, electronic engineering, materials science, and material physics involving components, electronic devices such as lasers, laser diodes, LEDs, waveguides, etc. which operate by the propag ...

, elasto-optic,

photorefractive The photorefractive effect is a nonlinear optical effect seen in certain crystals and other materials that respond to light by altering their refractive index. The effect can be used to store temporary, erasable holograms and is useful for holog ...

and

photoconductive Photoconductivity is an optical and electrical phenomenon in which a material becomes more electrically conductive due to the absorption of electromagnetic radiation such as visible light, ultraviolet light, infrared light, or gamma radiation. Whe ...

properties, and therefore have potential applications in

spatial light modulator A spatial light modulator (SLM) is an object that imposes some form of spatially varying modulation on a beam of light. A simple example is an overhead projector transparency. Usually when the term SLM is used, it means that the transparency can ...

acoustic delay line Delay-line memory is a form of computer memory, now obsolete, that was used on some of the earliest digital computers. Like many modern forms of electronic computer memory, delay-line memory was a refreshable memory, but as opposed to modern r ...

s and

hologram Holography is a technique that enables a wavefront to be recorded and later re-constructed. Holography is best known as a method of generating real three-dimensional images, but it also has a wide range of other Holography#Applications, applic ...

recording equipment. Bi₁₂SiO₂₀ can be obtained as a whitish powder with band gap of approximately 3.2 eV starting from

bismuth subcarbonate Bismuth subcarbonate (BiO)2CO3, sometimes written Bi2O2(CO3) is a chemical compound of bismuth containing both oxide and carbonate anions. Bismuth is in the +3 oxidation state. Bismuth subcarbonate occurs naturally as the mineral bismutite. Its ...

and silica in presence of ethyleneglycol. ²⁹Si solid-state NMR is used to proof that the Si(IV) cations are sharing oxygen atoms with the Bi(III) cations. The ²⁹Si chemical shift (δ) in Bi₁₂SiO₂₀ is −78.1 ppm. Unlike the

bismuth oxide Bismuth(III) oxide is perhaps the most industrially important compound of bismuth. It is also a common starting point for bismuth chemistry. It is found naturally as the mineral bismite (monoclinic) and sphaerobismoite (tetragonal, much more rare) ...

, the presence of the acidic Si(IV) cations avoid the reactivity with CO₂. Another bismuth silicate has formula Bi₂O₉Si₃.

References

Bismuth compounds Inorganic silicon compounds Oxides {{Inorganic-compound-stub