Properties of barium-magnesium titanate dielectrics

George R. Shelton, Ansel S. Creamer, Elmer N. Bunting
1948 Journal of research of the National Bureau of Standards  
Dielectrics having compositions in the system BaTiO3-4MgO:TiO2-TiO2 were matured (less than 0.1% of absorption) at 1,275° to 1,425° C. Data are given for the dielectric constant K at a frequency of 1 mc/s and various temperatures from -60° to + 85° C, and for Q, the reciprocal of the power factor, at 25° C and frequencies of 50, 1,000, and 20,000 kc/s and 3,000 mc/s. Values of K (1 mc/s and 25° C) ranged from 12 to 1,550 and those of Q from 9 to 10,000. Values of K decreased, and those of Q
more » ... and those of Q increased for several weeks after specimens were matured, when the content of BaO was greater than 30 percent and that of TiO 2 less than 50 percent. Partial restoration of the original values of K and Q resulted from heating these specimens at various temperatures for brief periods. Linear thermal expansion (25° to 700° C) ranged from 0.46 to 0.71 percent. A few specimens of bariumstrontium titanate were tested for the effects of thermal history on the properties.
doi:10.6028/jres.041.004 fatcat:dqa7s6z7pje5hif4byd6uaddai