GB977596A - Improvements in or relating to ferromagnetic compounds - Google Patents

Abstract

Novel binary and ternary inorganic compounds having ferromagnetic properties have the formula ABx where x is 2 or 5, A is praseodymium, neodymium, samarium, yttrium, europium, gadolinium, terbium, dysprosium, holmium, erbium or thulium, or when x is 5 and B is cobalt may be a mixture of gadolinium and yttrium; and B is iron, cobalt or magnanese, or when x is 5 and A is dysprosium may be a mixture of iron and nickel. These compounds are extensively exemplified and are characterized in terms of their density, magnetic properties and molecular structure. The compounds are prepared by melting and mixing the appropriate pure metals in the proportions required to give the desired compound by levitation melting in an inert atmosphere, e.g. argon, and in the high-frequency field of an induction coil, stirring the mixture electro-magnetically while in the field of the coil, rapidly cooling the product by dropping the molten material into a metallic (e.g. copper) mould to solidify the melt, and recovering the desired compound. The melting technique may be varied according to the sizes of the metal pieces. Thus, two pieces of metal of the same size may be levitated together and mixed when melted; if one piece is larger than the other the small piece may be placed in the mould and the large piece levitation melted on to it, the two pieces adhering together and then being levitated as one piece and remelted; and in a third method one piece of metal can be dropped into a piece of molted metal in a magnetically-operated hopper.ALSO:Novel binary and ternary inorganic compounds having ferromagnetic properties have the formula ABx where x is 2 or 5, A is praseodymium, neodymium, samarium, yttrium, europium, gadolinium, terbium, dysprosium, holmium, erbium, or thutium, or when x is 5 and B is cobalt may be a mixture of gadolium and yttrium; and B is iron, cobalt, or manganese, or when x is 5 and A is dysprosium may be a mixture of iron and nickel. These compounds are extensively exemplified and are characterized in terms of their density, magnetic properties and molecular structure. The compounds are prepared by melting and mixing the appropriate pure metals in the proportions required to give the desired compound by levitation melting in an inert atmosphere, e.g. argon, and in the high frequency field of an induction coil, stirring the mixture electromagnetically while in the field of the coil, rapidly cooling the product by dropping the molten material into a metallic (e.g. copper) mould to solidify the melt, and recovering the desired compound. The melting technique may be varied according to the sizes of the metal pieces. Thus, two pieces of metal of the same size may be levitated together and mixed when melted; if one piece is larger than the other the small piece may be placed in the mould and the large piece levitation melted on to it, the two pieces adhering together and then being levitated as one piece and remelted; and in a third method one piece of metal can be dropped into a piece of molten metal in a magnetically operated hopper.