We are developing a room temperature vacuum system to measure magneto-electric properties of epitaxial samples. This system will have its temperature accurately controlled using a high performance Peltier device and we aim to measure, among other things, the hall resistances of the sample very precisely using a nano-voltmeter.

The design of the vacuum chamber, the heat sinking and all other aspects are covered, we are only stuck with the actual sample connections. Here are a few key points in the design brief for such a sample connector:

• The sample will be bonded to the sample holder which is connected to the sample stage. The sample pertains to the piece of wafer of our material, the sample holder is a piece which the material is bonded to and holds the electrical contacts and the sample stage is the socket in the chamber which makes contact to the wires for the measurement equipment.
• The sample of material must be as close to the temperature of the copper surround as possible, preferably using an electrically insulating, and thermally conductive material as the base.
• The header requires at least 8 contacts, preferably 12 or more.
• The sample holder must be easily removable and replaceable, preferably readily available or easily manufactured.
• The materials used must be vacuum safe.
• Any metals must be copper, silver or gold to eliminate any significant thermal voltages. There must not be able tin, nickel or iron (and ofcs not cobalt).
• Any other materials must be non-magnetic.
• The temperature range of operation will be -30C to 100C at the extremes.

It seems like this sort of thing must have been done. Surely people have made thermal voltage measurements on magnetic materials in a vacuum before? no? If anyone has some ideas please let me know.

Thank you for reading and any feedback you may have.

Best wishes,

Stu