Device for mounting semiconductor rods in apparatus for crucible-free zone melting

Apparatus for securing a rod of semi-conductor material in equipment for crucible-free zone-by-zone melting comprises six pins 4 of a material which has a high melting point and which does not diffuse into the semi-conductor material, the pins being arranged in two sets of three and pivotally mounted in a hollow carrier member 2 which in the use of the apparatus is to have the rod 5 co-axially within it, means 6 being provided to hold the pins against the semi-conductor rod, the arrangement being such that in the use of the apparatus the pins bear resiliently against the rod one set of pins touching the rod at three contact points in one plane which are equally spaced around the periphery of the rod and the other set of pins touching the rod at three contact points in another plane which are equally spaced around the periphery said planes being perpendicular to the axis of the carrier member. As shown the pins 4 are rigidly secured to pivoted arms 3 and the means 6 are screws which are threaded into the carrier member 2. The pins are made of molybdenum and the remainder of the apparatus is made of a high alloy steel containing about 90% chromium and about 9% nickel to give low thermal conductivity. Recesses 7 are provided in the carrier member to introduce additional thermal resistance between the rods and the device 9 upon which the carrier member 2 is mounted. The carrier member is clamped to the device 9 by a jaw 10 which is urged into contact with a pin 8 of a screw 11.