Dielectric magnesium compounds

In addition to the multilayered ceramic capacitors just described, many of the barium titanate-based compounds that exhibit high dielectric constants are used in single-layer tape-cast capacitor devices. Relaxor materials such as lead magnesium niobate (PMN), which are characterized by high dielectric constants, broad dielectric maxima, and low sintering temperatures, have been manufactured in thin sheets by tape casting. 

A chemical compound made up from elements such as titanium, niobium, lead, magnesium, and oxygen, which can have an extremely high dielectric constant (sometimes more than 20,000). These can also be piezoelectric, with very good properties. 

Magnesium Titanates. Three compounds exist. Mg2Ti04, m.p. 1730 C this has a spinel structure and has been proposed for use as a resistor. MgTi03, m.p. 1630°C ilmenite structure. MgTi205, m.p. 1650°C has a low dielectric constant and has been added to other titanate bodies to reduce their dielectric constants. 

Magnesium Zirconate. MgZr03 m.p. 2150°C. This compound is sometimes added in small amounts (up to 5%) to other electroceramic bodies to lower their dielectric constant at the Curie point. 

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