Small sample measurements at the low energy muon facility of Paul Scherrer Institute

TL;DR

This paper reports advancements in low energy muon spin rotation spectroscopy at PSI, enabling measurements on smaller samples down to 5x5 mm² and introducing a method to measure multiple small samples simultaneously, enhancing efficiency.

Contribution

The study introduces techniques for measuring smaller samples and a new method for simultaneous measurement of multiple samples at PSI's LEM facility.

Findings

Achieved measurement of samples as small as 5x5 mm²

Developed a method to measure five small samples simultaneously

Enhanced efficiency of beam time utilization

Abstract

The low energy muon spin rotation spectroscopy (LE-$\mu$SR) is primarily used to investigate thin films, surfaces, and interfaces of materials, which has matured at the Paul Scherrer Institute (PSI) and is routinely employed by users of the low energy muon (LEM) facility. However, because of the large beam spot and low implanted muons rate, LE-$\mu$SR measurements on small samples are difficult, requiring an optimal sample size of $25\times25$ mm$^2$. Recently, we have boosted our ability to measure small samples, down to $5\times5$ mm$^2$ area, by beam collimation and tuning. This achievement is crucial for the measurements of many magnetic and superconducting materials. Furthermore, we have devised a method that allows us to measure five small area samples mounted together on the same sample plate. We expect this method to further improve the efficient use of beam time at LEM.