Thermal spike in muon implantation

Abstract

In muon spin rotation experiments, the diamagnetic fraction observed at low temperatures is a consequence of the muon interaction with the lattice during the incorporation process and depends on the properties of the material. An increase of the diamagnetic fraction with decreasing temperature is observed in some cases, which we attribute to a thermal spike at the end of the muon trajectory. The thermal spike is due to energy liberated not only during the muon stopping process but also as a consequence of the stress release when the electron bound to a muon in a unrelaxed configuration jumps to a neighboring lattice site. The magnitude and time extension of this effect is more significant for highly disturbed lattices which exhibit very low thermal conductivities at low temperatures. A phenomenological description of some selected examples is presented, together with a discussion about heat transport, using existing models for the thermal spike.

CdS versus ZnSnO buffer layers for a CIGS solar cell: a depth-resolved analysis using the muon probe

“…The diamagnetic fraction was found to be smaller than unity for most of the measurements. This indicates that the muons experience a strong interaction during their implantation stage, reducing the formation probability of the final bound configuration [4,[8][9][10][11][12][13].…”

Direct Observation of Hole Carrier-Density Profiles and Their Light-Induced Manipulation at the Surface ofGe

“…In the bulk of the sample, this effect obviously does not occur. In contrast, in the surface region with presumably larger lattice distortions [29], causing a reduced thermal conductivity, the thermal spike effect can explain the increase of F D .…”

“…The increase of F D in the undoped sample at T < 50 K can be explained within the thermal spike model [29]. Here, excess heat (due to energy liberated during the stopping process and also as a consequence of stress release to reach the final lattice configuration around the thermalized Mu 0 ) may not be quickly enough released to the surrounding lattice due to a reduced thermal conductivity at low temperatures.…”

Modelling isolated hydrogen impurity in Lu2O3 with muonium spectroscopy

“…The red dashed line is a fit to a "thermal spike model" (see below and Ref. [17]). The black lines are fits to Boltzmann functions as discussed in the text.…”

“…We call it a thermal spike since it disappears quickly in particular if the temperature is increased. This excitation energy imitates a higher temperatures and can induce reactions which otherwise occur only at higher temperature [17].…”