Electroceramics

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Electroceramics are a class of ceramic materials used primarily for their electrical properties.

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While ceramics have traditionally been admired and used for their mechanical, thermal and chemical stability, their unique electrical, optical and magnetic properties have become of increasing importance in many key technologies including communications, energy conversion and storage, electronics and automation. Such materials are now classified under electroceramics, as distinguished from other functional ceramics such as advanced structural ceramics.

Historically, developments in the various subclasses of electroceramics have paralleled the growth of new technologies. Examples include: ferroelectrics - high dielectric capacitors, non-volatile memories; ferrites - data and information storage; solid electrolytes - energy storage and conversion; piezoelectrics - sonar; semiconducting oxides - environmental monitoring. Recent advances in these areas are described in the Journal of Electroceramics.

Dielectric ceramics

Dielectric materials used for construction of ceramic capacitors include: Lead Zirconate titanate (PZT), Barium titanate(BT), strontium titanate (ST), calcium titanate (CT), magnesium titanate (MT), calcium magnesium titanate (CMT), zinc titanate (ZT), lanthanum titanate (LT), and neodymium titanate (NT), barium zirconate (BZ), calcium zirconate (CZ), lead magnesium niobate (PMN), lead zinc niobate (PZN), lithium niobate (LN), barium stannate (BS), calcium stannate (CS), magnesium aluminium silicate, magnesium silicate, barium tantalate, titanium dioxide, niobium oxide, zirconia, silica, sapphire, beryllium oxide, and zirconium tin titanate

Some piezoelectric materials can be used as well; the EIA Class 2 dielectrics are based on mixtures rich on barium titanate. In turn, EIA Class 1 dielectrics contain little or no barium titanate.

Electronically conductive ceramics

Indium tin oxide (ITO), lanthanum-doped strontium titanate (SLT), yttrium-doped strontium titanate (SYT)

Fast ion conductor ceramics

Yttria-stabilized zirconia (YSZ), gadolinium-doped ceria (GDC), lanthanum strontium gallate magnesite(LSGM), beta alumina, beta alumina

Piezoelectric and ferroelectric ceramics

Commercially used piezoceramic is primarily lead zirconate titanate (PZT). Barium titanate (BT), strontium titanate (ST), quartz, and others are also used.

See Category:Piezoelectric materials.

Magnetic ceramics

Ferrites including iron(III) oxide and strontium carbonate display magnetic properties. Lanthanum strontium manganite exhibits colossal magnetoresistance.

See also

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In electromagnetism, a dielectric is an electrical insulator that can be polarised by an applied electric field. When a dielectric material is placed in an electric field, electric charges do not flow through the material as they do in an electrical conductor, because they have no loosely bound, or free, electrons that may drift through the material, but instead they shift, only slightly, from their average equilibrium positions, causing dielectric polarisation. Because of dielectric polarisation, positive charges are displaced in the direction of the field and negative charges shift in the direction opposite to the field. This creates an internal electric field that reduces the overall field within the dielectric itself. If a dielectric is composed of weakly bonded molecules, those molecules not only become polarised, but also reorient so that their symmetry axes align to the field.

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