Low temperature microwave emission from molecular clusters

TL;DR

This study experimentally detects microwave radiation emitted during rapid magnetization reversal in Mn12-acetate at low temperatures, revealing a sequential process involving magnetic inversion, radiation emission, and temperature change.

Contribution

It provides the first experimental observation of microwave emission during fast magnetization reversal in molecular magnets at low temperatures.

Findings

Detected microwave radiation coincides with magnetization reversal

Radiation emission occurs before temperature increase

Magnetic and thermal dynamics are sequential and measurable

Abstract

We investigate the experimental detection of the electromagnetic radiation generated in the fast magnetization reversal in Mn12-acetate at low temperatures. In our experiments we used large single crystals and assemblies of several small single crystals of Mn12-acetate placed inside a cylindrical stainless steel waveguide in which an InSb hot electron device was also placed to detect the radiation. All this was set inside a SQUID magnetometer that allowed to change the magnetic field and measure the magnetic moment and the temperature of the sample as the InSb detected simultaneously the radiation emitted from the molecular magnets. Our data show a sequential process in which the fast inversion of the magnetic moment first occurs, then the radiation is detected by the InSb device, and finally the temperature of the sample increases during 15 ms to subsequently recover its original value in several hundreds of milliseconds.