Evonik Degussa Gmbh

Degussa Aktiengesellschaft

Paul Roth

Markus Pridoehl

Hartmut Wiggers

Michael Kraemer

Frank-Martin Petrat

Guido Zimmermann

Markus Pridöhl

Heiko Gottfried

Berthold Trageser

Christian Janzen

An aggregated crystalline silicon powder with a BET surface area of 20 to 150 m/g is provided. The aggregated silicon powder may be doped with phosphorus, arsenic, antimony, bismuth, boron, aluminium, gallium, indium, thallium, europium, erbium, cerium, praseodymium, neodymium, samarium, gadolinium, terbium, dysprosium, holmium, thulium, lutetium, lithium, ytterbium, germanium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, or zinc.

Nanoscale crystalline silicon powder

An aggregated crystalline silicon powder with a BET surface area of 20 to 150 m/g is provided. The aggregated crystalline silicon may be doped with a doping component and can be used to produce electronic components.

Aggregated crystalline silicon powder with a BET surface area of 20 to 150 m/g. It is prepared by subjecting at least one vaporous or gaseous silane and optionally at least one vaporous or gaseous doping material, an inert gas and hydrogen to heat in a hot wall reactor, cooling the reaction mixture or allowing the reaction mixture to cool and separating the product from gaseous substances in the form of a powder, wherein the proportion of silane is between 0.1 and 90 wt. %, with respect to the sum of silane, doping material, hydrogen and inert gases, and wherein the proportion of hydrogen, with respect to the sum of hydrogen, silane, inert gas and doping material, is in the range 1 mol. % to 96 mol. %. It can be used to produce electronic components.

Pyrogenic, oxidic particles contain superparamagnetic metal oxide domains with a diameter of 3 to 20 nm in a non-magnetic metal or non-metal oxide matrix. The particles display a chloride content of 50 to 1000 ppm. The particles are produced by pyrogenic processes by mixing the precursor of the superparamagnetic domains and the precursor of the non-magnetic metal or non-metal oxide matrix in a flame with air and/or oxygen and fuel gas and reacting this mixture in a flame. The particles can be used as ferro fluids, for example.

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Kempen, Germany

Paul Roth