Abstract: A thermistor based on a composition having the general formula (I): Re2-x-yCraMnbMcEyOz wherein Re is a rare earth metal or a mixture of two or more rare earth metals, M is a metal selected from the group consisting of nickel, cobalt, copper, magnesium and mixtures thereof, E is a metal selected from the group consisting of calcium, strontium, barium and mixtures thereof, x is the sum of a+b+c and is a number between 0.1 and 1, and the relative ratio of the molar fractions a, b and c is in an area bounded by points A, B, C and D in a ternary diagram, wherein point A is, if y<0.006, at (Cr=0.00, Mn=0.93+10?y, M=0.07?10?y), and, if y?0.006, at (Cr=0?00, Mn=0.99, M=0.01), point B is, if y<0.006, at (Cr=0.83, Mn=0.10+10?y, M=0.07?10?y), and, if y?0.006, at (Cr=0.83, Mn=0.16, M=0.01), point C is at (Cr=0.50, Mn=0.10, M=0.40) and point D is at (Cr=0.00, Mn=0.51, M=0.49), y is a number between 0 and 0.5?x, and z is a number between 2.5 and 3.5.

Abstract: A thermistor based on a composition having the general formula (I): Re2-x-yCraMnbMcEyOz wherein Re is a rare earth metal or a mixture of two or more rare earth metals, M is a metal selected from the group consisting of nickel, cobalt, copper, magnesium and mixtures thereof, E is a metal selected from the group consisting of calcium, strontium, barium and mixtures thereof, x is the sum of a+b+c and is a number between 0.1 and 1, and the relative ratio of the molar fractions a, b and c is in an area bounded by points A, B, C and D in a ternary diagram, wherein point A is, if y<0.006, at (Cr=0.00, Mn=0.93+10-y, M=0.07-10-y), and, if y?0.006, at (Cr=0-00, Mn=0.99, M=0.01), point B is, if y<0.006, at (Cr=0.83, Mn=0.10+10-y, M=0.07?10-y), and, if y?0.006, at (Cr=0.83, Mn=0.16, M=0.01), point C is at (Cr=0.50, Mn=0.10, M=0.40) and point D is at (Cr=0.00, Mn=0.51, M=0.49), y is a number between 0 and 0.5-x, and z is a number between 2.5 and 3.5.

Abstract: The invention is directed to hydrogen absorbing compounds which are useful for storing, keeping and releasing hydrogen gas. Such compounds have the formula La.sub.x Ce 1-.sub.x Ni.sub.5 where x lies between 0.4 and 1. The compounds may also be lanthanium/nicklel compounds which contain copper zirconium or yttrium.

Abstract: A hydrogen storage and supply device in which a pressure vessel contains a hydride of the gross formula AB.sub.n H.sub.m, in which A is calcium or one or more of the rare earth metals with or without thorium, zirconium, or hafnium, B is nickel and/or cobalt, with or without iron and/or copper, n has a value between about 3 and 8.5 and m has a value exceeding 0 and up to about 7.

Abstract: A hydride of the gross formula AB.sub.n H.sub.m, in which A is calcium or one or more of the rare earth metals with or without thorium, zirconium, or hafnium, B is nickel and/or cobalt, with or without iron and/or copper, n has a value between about 3 and 8.5 and m has a value up to about 7.

Abstract: An electrochemical energy conversion device, i.e. a galvanic cell using a hydrogen absorbing material to provide either a source of energy, or to absorb hydrogen to avoid overpressure in the cell. This hydrogen absorbing material is a compound of the formula LnM.sub.5 in which Ln represents a lanthanide metal and M is either cobalt or nickel.