Quantifying Crystal Defect Densities in Rare-Earth-Doped Crystals by Gravimetric Analysis

Robert D. Kwapisz, Charles W. Thiel and Rufus L. Cone, Physics, Montana State University, Barnard Hall, 59717

Quantifying the nature and density of lattice defects in high-quality crystals is often very difficult or impossible with commonly used material characterization techniques. In most cases, even the density of intentionally doped impurities present in a grown crystal must be inferred indirectly using methods such as mapping spatial variations in crystal properties. In this work we propose exploring gravimetric techniques to obtain absolute defect densities in crystals, a powerful approach that has been often overlooked in modern materials science. 

A hydrostatic weighing apparatus based on Archimedes’s principle was constructed and tested to enable high-precision density measurements of small crystal samples. This system was used to determine the density of thulium and ytterbium ions doped into different garnet crystals. High-purity silicon and titanium samples were used as known density references, avoiding the traditional difficulties in correcting for the significant change in water density due to very small ambient temperature and pressure variations. This method was effective in defect concentrations in YAG and YGG crystals, as well as providing insight into the intrinsic lattice defects such as the concentration of Y-Al antisites. Consequently, the gravimetric method is a promising technique for characterizing new materials developed for applications ranging from solid-state lasers and scintillators to quantum information.



Additional Abstract Information

Presenter: Robert Kwapisz

Institution: Montana State University

Type: Poster

Subject: Physics/Astronomy

Status: Approved

Time and Location

Session: Poster 9
Date/Time: Wed 12:00pm-1:00pm
Session Number: 6133