초록

where M.sup.2+ is a divalent metal, M.sup.3+ is a trivalent metal, and T is vanadium, tungsten, or molybdenum.

대표청구항 ▼

[ We claim:] [1.] A composition which comprises:microcrystallites collectively of the formula: EQU M.sub.2m.sup.2+ Al.sub.2-p M.sub.p.sup.3+ T.sub.r O.sub.7+r.multidot.s rem is about 1.1 to about 3.5;p is about 0.01 to about 0.4;M.sup.2+ is a divalent metal selected from the group consisting of magn

[ We claim:] [1.] A composition which comprises:microcrystallites collectively of the formula: EQU M.sub.2m.sup.2+ Al.sub.2-p M.sub.p.sup.3+ T.sub.r O.sub.7+r.multidot.s rem is about 1.1 to about 3.5;p is about 0.01 to about 0.4;M.sup.2+ is a divalent metal selected from the group consisting of magnesium, calcium, zinc, barium, and strontium;M.sup.3+ is a trivalent metal selected from the group consisting of cerium, lanthanum, iron, chromium, vanadium, and cobalt;T is vanadium, tungsten or molybdenum;r is about 0.01 to about 0.2;s is 2.5 when T is vanadium or 3 when T is tungsten or molybdenum;wherein the microcrystallites are substantially composed of solid solution microcrystallites having aluminum oxide dispersed in a monoxide of the divalent metal, each of the microcrystallites having a greatest linear dimension in the range of about 0.1 to about 30 nanometers.