| AVS 54th International Symposium | |
| Surface Science | Tuesday Sessions |
| Session SS-TuP |
| Session: | Surface Science Poster Session |
| Presenter: | D.M. Rampulla, Princeton University |
| Authors: | D.M. Rampulla, Princeton University S.J. Seltzer, Princeton University M. Romalis, Princeton University S.L. Bernasek, Princeton University |
| Correspondent: | Click to Email |
Atomic magnetometers containing spin-polarized alkali-metal atoms are capable of detecting magnetic fields with a sensitivity superior to that found in SQUIDs; however, a current issue with atomic magnetometers are depolarizing collisions between alkali-metal atoms and the cell walls. An inert buffer gas can be used to slow diffusion of spin-polarized alkali-metal atoms to cell walls, but a preferable solution would be a high-quality antirelaxation surface coating that would diminish the depolarization events that lead to the loss of spin-coherence and reduce the need for buffer gas. Although some coatings have been proven effective, paraffin and others presently in use typically can not operate at the relatively high temperatures (T > 100°C) for cesium and (T > 150°C) for potassium required for high-density magnetometers; therefore, it is desirable to find an effective antirelaxation coating suitable for these temperatures. In previous work, we have found that a coating of octadecyltrichlorosilane (OTS) at T > 150°C can allow a potassium atom to collide more than 2000 times with the walls of a spherical borosilicate glass cell before depolarizing. However, spherical glass cells are not easily studied with surface science techniques (X-ray photoelectron spectroscopy and reflection-absorption infrared spectroscopy), thus we constructed a reusable alkali vapor cell for measuring antirelaxation properties of multiple flat surfaces coated with various monolayers (chlorosilanes and phosphonic acids). In addition to antirelaxation properties, the coatings were tested for reactivity toward alkali metals and temperature stability.