musrfit: A free platform-independent framework for muSR data analysis

A free data-analysis framework for muSR has been developed. musrfit is fully written in C++, is running under GNU/Linux, Mac OS X, as well as Microsoft Windows, and is distributed under the terms of the GNU GPL. It is based on the CERN ROOT framework and is utilizing the Minuit optimization routines for fitting. It consists of a set of programs allowing the user to analyze and visualize the data. The fitting process is controlled by an ascii-input file with an extended syntax. A dedicated text editor is helping the user to create and handle these files in an efficient way, execute the fitting, show the data, get online help, and so on. A versatile tool for the generation of new input files and the extraction of fit parameters is provided as well. musrfit facilitates a plugin mechanism allowing to invoke user-defined functions. Hence, the functionality of the framework can be extended with a minimal amount of overhead for the user. Currently, musrfit can read the following facility raw-data files: PSI-BIN, MDU (PSI), ROOT (LEM/PSI), WKM (outdated ascii format), MUD (TRIUMF), NeXus (ISIS).Comment: 4 pages, 4 figure

Zero-field spin depolarization of low-energy muons in ferromagnetic nickel and silver metal

We present zero-fieldmuon-spindepolarization measurements in nickel and silver performed using low-energymuon-spin relaxation technique.Ni or Ag are usually used in this depth-resolved technique as a backing material to enable background subtraction when studying small crystals or materials with weak magnetism. The depolarization rate of the asymmetry in silver and that of the slow relaxing part of the asymmetry in nickel are small(≤ 0.05 μs−1), and weakly temperature and energy-dependent

Absolute value and anisotropy of the magnetic penetration depth in YBa2Cu3O6.92

The absolute value and anisotropy of the magnetic penetration depth have been measured in a mosaic of optimally-doped YBa2Cu3O6.92 crystals using low-energy muon spin rotation at 8 K with extrapolation to T = 0 using microwave resonator data. The average magnetic field was measured as a function of muon implantation energy in a small magnetic field applied along the â and directions. Beyond a depth d, the magnetic field profiles are consistent with the simple exponential decay of the internal field expected from a London model. The results are compared with other less direct methods