Low temperature sintering of Mg-Mn-Zn ferrites

Abstract

A method to lower sintering temperature of ferrites was studied. It was found that the sintering temperature could be reduced remarkably by means of both substitution of lithium and addition of lithium borosilicate glasses to Mg-Mn-Zn ferrites, which is used for television deflection yokes. For example, when lithium borosilicate glass containing 20 mol% Li <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O, 40 mol% B <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> and 40 mol% SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> is added to lithium substituted Mg-Mn-Zn ferrite with a composition of Mg <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.64</inf> Mn <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.06</inf> Li <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.04</inf> Zn <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.23</inf> Fe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2.03</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3.99</inf> ,the sintering temperature decreases by 200°C as compared with that of Mg-Mn-Zn ferrite. Particularly, Li-Zn ferrite with addition of this glass can be sintered at 800°C. In ferrites prepared by liquid phase sintering, the magnetic properties often become worse, but with this method, the properties remain almost the same as those of the mother ferrites.