Patent ID: 7652415

Claim:
An electrode comprising an electron emissive material, wherein the electron emissive material comprises an alkaline earth metal halide compound of formula (I), (II), (III) or (IV), wherein MXZ, (I) wherein M is at least one alkaline earth metal selected from the group consisting of magnesium, calcium, strontium, barium, and combinations thereof, X is a first halogen selected from the group consisting of fluorine, chlorine, bromine iodine, and combinations thereof and Z is a second halogen different from the first halogen and selected from group consisting of fluorine, chlorine, bromine, iodine and combinations thereof; MX l Z m O n/2 (II) wherein M is at least one alkaline earth metal selected from the group consisting of magnesium, calcium, strontium, barium and combinations thereof, X is at least one halogen selected from the group consisting of fluorine, chlorine, bromine, iodine and combinations thereof, Z is at least one halogen different from the first halogen and selected from group consisting of fluorine, chlorine, bromine, iodine and combinations thereof, wherein l, m, and n is selected to maintain charge balance and where l is selected to be in a range from greater than or equivalent to 0 to less than or equivalent to 2, m is selected to be in a range from greater than or equivalent to 0 to less than or equivalent to 1, and n is selected to be less than or equivalent to 0.5; MX b O c N d (III) wherein M is at least one alkaline earth metal selected from the group consisting of magnesium, calcium, strontium, barium and combinations thereof, X is at least one halogen selected from the group consisting of fluorine, chlorine, bromine, iodine and combinations thereof where b, c, d is selected to maintain charge balance and b is be selected to be in a range from greater than 0 to about 2, c is selected to be in a range from 0 to about 1, and d is selected to be in a range from 0 to about 1; and A e M f R g O h X i (IV) wherein A is at least one alkali metal selected from the group consisting of sodium, potassium, and combinations thereof, M is at least one alkaline earth metal selected from the group consisting of magnesium, calcium, strontium, barium and combinations thereof, R is a metal selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, Sc, and combinations thereof X is at least one halogen selected from the group consisting of fluorine, chlorine, bromine, iodine and combinations thereof where e, f, g, h, I, is selected to maintain charge balance and e may be selected to be in a range from 0 to about 3, f may be selected to be in a range from greater than 0 to about 4, g may be selected to be in a range from about 0 to about 3, h may be selected to be in a range from 0 to about 1 and i may be selected to be in a range from about 2 to about 11.