Composition and method

Abstract

A method includes contacting a transition metal oxide, a sintering additive, and a grain growth inhibitor additive to form a mixture. The transition metal oxide include particles that have an average diameter less than about 1 micrometer and treating the mixture to a temperature profile that is sufficiently high that a sintered mass is formed from the mixture. The thermal profile is less than about 1050 degrees Celsius.

1 . A method, comprising:
 contacting a transition metal oxide, a sintering additive, and a grain growth inhibitor additive to form a mixture, wherein the transition metal oxide comprises particles that have an average diameter less than about 1 micrometer; and   sintering the mixture at a temperature profile that is sufficiently high that a sintered mass is formed from the mixture, and the thermal profile is less than about 1050 degrees Celsius.   
   
   
       2 . The method of  claim 1 , wherein treating the mixture comprises exposure to a sinter temperature that is in a range from about 700 degrees Celsius to about 1050 degrees Celsius. 
   
   
       3 . The method of  claim 1 , further comprising calcining the transition metal oxide and the sintering additive together before forming the mixture, and the calcining comprises heating to a temperature of about 400 degress Celsius. 
   
   
       4 . The method of  claim 1 , further comprising contacting the sintered mass with an electrically conductive material, and forming a electrical connection therebetween. 
   
   
       5 . The method as defined in  claim 4 , wherein the electrically conductive material has a melting point that is less than 1050 degrees Celsius, and forming the electrical connection comprises forming the electrically conductive material into an electrode. 
   
   
       6 . The method as defined in  claim 1 , further comprising selecting the sintering additive to comprise one or more of lithium, antimony, bismuth, cobalt, manganese, or silicon. 
   
   
       7 . The method as defined in  claim 6 , further comprising selecting the sintering additive to comprise one or both of LiBiO 3 , or Li 2 CO 3 . 
   
   
       8 . The method as defined in  claim 1 , further comprising selecting the transition metal oxide to be present in an amount that is greater than about 80 percent by weight, based on the total weight of the the sintered mass. 
   
   
       9 . The method as defined in  claim 1 , further comprising selecting the amount of the sintering additive to be less than about 15 percent by weight, based on the total weight of the the sintered mass. 
   
   
       10 . The method as defined in  claim 1 , further comprising selecting the grain growth inhibitor additive to comprise one or more of SiO 2 , Sb 2 O 3 , CaO, Al 2 O 3 , MgO, or Fe 2 O 3 . 
   
   
       11 . The method as defined in  claim 1 , further comprising selecting the grain growth inhibitor additive to be present in an amount that is less than about 10 percent by weight, based on the total weight of the the sintered mass. 
   
   
       12 . The method as defined in  claim 1 , further comprising adding a a grain boundary additive to the mixture prior to sintering. 
   
   
       13 . The method as defined in  claim 12 , further comprising selecting the grain boundary additive to comprise Co 3 O 4 , Cr 2 O 3 , Bi 2 O 3 , Pr 2 O 3 , NiO, or SnO 2 . 
   
   
       14 . The method as defined in  claim 12 , further comprising selecting the amount of the grain boundary additive to be less than about 10 percent by weight, based on the total weight of the the sintered mass. 
   
   
       15 . The method as defined in  claim 1 , wherein the sintered mass comprises a plurality of cores, and the temperature profile and a an average particle size of the transition metal oxide are selected to form an average distance from one core to an adjacent core in the plurality of cores is less than about 1 micrometer after sintering. 
   
   
       16 . The method as defined in  claim 15 , wherein the average diameter of the cores is less than about 1 micrometer. 
   
   
       17 . The method as defined in  claim 15 , wherein the cores are separated from each other by a grain boundary layer, and a mean value for a thickness of the grain boundary layer is less than 50 nanometers. 
   
   
       18 . The method as defined in  claim 17 , wherein the cores each define a grain boundary in the sintered mass, and an average distance from a grain boundary of one core to a grain boundary of an adjacent core in the sintered mass is less than about 1 micrometer. 
   
   
       19 . The method as defined in  claim 12 , wherein selecting the grain boundary additive results in the average thickness of the grain boundary layer being less than about 400 nanometer. 
   
   
       20 . The method as defined in  claim 1 , further comprising subjecting the sintered mass to an electrical potential, and the sintered mass exhibits a dielectric strength or breakdown field of greater than about 0.5 kV/mm. 
   
   
       21 . The method as defined in  claim 20 , wherein the sintered mass has a non-linearity coefficient (α) of greater than about 25. 
   
   
       22 . The method as defined in  claim 1 , further comprising forming the sintered mass with a homogenous microstructure. 
   
   
       23 . A method, comprising:
 contacting a transition metal oxide with a sintering additive to form a premix, wherein the transition metal oxide comprises particles that have an average diameter less than about 1 micrometer;   calcining the premix, wherein the calcining comprises heating to a temperature of about 400 degress Celsius to provide a calcined mass;   contacting the calcined mass with a grain growth inhibitor additive to form a mixture; and   sintering the mixture at a temperature profile that is sufficiently high that a sintered mass is formed from the mixture, and the thermal profile is less than about 1050 degrees Celsius.   
   
   
       24 . A method, comprising:
 contacting a transition metal oxide, a sintering additive, and a grain growth inhibitor additive to form a mixture, wherein the transition metal oxide comprises particles that have an average diameter less than about 1 micrometer; and   sintering the mixture at less than about 1050 degrees Celsius to form a sintered mass, and while sintering forming an electrode from an electrically conductive material.