Preparation and Properties of a Stable Metallic Ferrofluid.
Abstract
The aim of this research work has been to obtain a suspension of small single domain ferromagnetic particles in a metallic carrier stable in high magnetic fields and over a temperature range suitable for its application in an energy convertor. An ultra stable suspension of iron particles in mercury containing 0.7 wt % of tin and approximately 2 wt % of sodium has been produced. This fluid is stable up to 420K and in zero magnetic field over the period of time during which measurements have been made, i.e. approximately one year. To date measurements have not been made above 420K. Theory predicts that the fluid as described above would be sufficiently stable in a magnetic field gradient of 100,000 oersted/cm to enable it to be used in an energy converter. However, initial experiments have shown that the effective rate of diffusion of iron particles under the influence of such a field gradient is many orders of magnitude greater than predicted.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1976
- Accession Number
- ADA036215
Entities
People
- J. Popplewell
- S. W. Charles
Organizations
- Bangor University