Magnetic and Structural Properties of Mn$_{\mathrm{5}}$Ge$_{\mathrm{3\thinspace }}$Nanoparticles*

Magnetic nanoparticles have unique and interesting properties which are scientifically important and attractive for numerous advanced technologies. In this work, we have used the cluster-beam deposition technique to synthesize Mn$_{\mathrm{5}}$Ge$_{\mathrm{3}}$ nanoparticles with different size. The composition, crystal structure and magnetic properties of the nanoparticles have been characterized by energy dispersive x-ray spectroscopy (EDS), X-ray diffraction, high-resolution transmission electron microscopy (HR-TEM) and magnetometry, respectively. Particles made with 1.7 Torr Argon pressure, and power of 80 W had an average size of 14 nm. Selected area electron diffraction showed that the particles had a hexagonal Mn$_{\mathrm{5}}$Si$_{\mathrm{3}}$-type structure with space group P63/mcm which is the same as in bulk. Magnetic measurements showed that the nanoparticles are ferromagnetic with a Curie temperature near room temperature. The effects of particle size and temperature on the magnetic properties are currently being studied and the results will be reported and discussed.