Contact: Prof. Hugo Keller

Team spring 2004

Magnetic field penetration profiles for a 16O substituted and a 18O substituted YBa2Cu3O7-d film measured directly by the low energy muon technique, clearly showing a pronounced isotope effect on the magnetic penetration depth.

The research interest of the group of Prof. Keller is focused on the study of microscopic magnetic properties and oxygen isotope effects of high-temperature superconductors and related materials by various complementary experimental techniques such as, SQUID and torque magnetometry, as well as resonance techniques (NMR/ NQR/ EPR/ μSR). Prof. Schilling and his group focus on thermal transport and vortex-related phases in type-II superconductors.

The novel low-energy μSR method developed by PD Dr Morenzoni and coworkers at PSI is a main tool in the research field of the group. Low-energy muons of tuneable energy can be implanted at a controllable (10-200nm) depth beneath the surface of the sample. This allows to study directly the distribution of local magnetic fields in thin samples, multi-layers, near surfaces, and as a function of depth below surfaces. At present PSI is the only place in the world where low-energy μSR experiments can be performed.

References:
R. Khasanov et al., Phys. Rev. Lett. 92, 057602 (2004).
R. Khasanov et al., Phys. Rev. B 68, 220506 (2003).

Read the scientific article published in MaNEP Newsletter No. 2 (PDF 144 Ko)
Read a basic introduction on muons as microscopic probes in condensed matter