Voigtian Kubo-Toyabe muon spin relaxation

The superposition of independent Gaussian and Lorentzian field distributions at an implanted muon site is shown, using Monte Carlo simulations, to result in a Voigtian generalization of the well known dynamic Kubo-Toyabe muon spin-relaxation function from which information on the internal field distribution within a sample can be recovered. The physical origins of the associated pseudo-Voigtian internal field distribution are discussed in the context of recent experimental zero-field mu SR results from spin-fluctuating and heavy-fermion systems.