This is a collaborative effort between Lamont-Doherty Geological Observatory and UCSB to study the magnetic behavior of pseudosingle domain particles. The work will utilize magnetic measurements on individual particles coupled with domain observations. The magnetic measurements will be extended from remanence measurements to weak field susceptibility and hysteresis determination. The particular topics are the following: 1. Additional tests of the existence of metastable single-domain like states in IRM(s), TRM and VRM. 2. The relationship between temperature dependence of domain structure and the TRM blocking process. 3. The physical nature of nucleation and pinning sites. 4. The role of nucleation in determining the response of PSD material to AF demagnetization. The last topic will lead to the application of new ideas on behavior of PSD particles to the interpretation of NRM.
