Recent progress in materials studies with a muon spin probe - From surface physics to life science

Spin-polarized muons, naturally available from the decay of accelerator-producing pions, with the help of anisotropic emission of energetic positrons/electrons, can be used to probe quite sensitively both the static and dynamic behaviors of the microscopic magnetic properties of various types of condensed matter. After historical developments, during the past 25 years, the following significant progress has been recently marked based upon mainly developments of advanced muon beams: (1) a consistent study of the magnetic phase diagram of high-T-c superconductors has revealed the existence of an anomalous anti-ferromagnetic phase in underdoped LaSrCuO; (2) the successful generation of a sub-keV mu(+) beam has brought us the capability of spin-dynamics studies of various surface magnetism; (3) the electron brought by the mu(+) during the slowing-down process was found to be useful for studies of electron transfer in proteins, (C) 2000 Elsevier Science B.V. All rights reserved.