Magnetic ordering in PrBCO by MaxEnt Muon-Spin Research*

Muon-Spin Research ($\mu $SR) is used to probe the magnetic ordering of PrBa2Cu3O7. The $\mu $SR PrBCO data are analyzed using the Maximum Entropy (ME) technique, a spectral analysis tool more sensitive than Fourier transformation. [1] At low temperature and zero applied field, muons are localized and their Larmor spin-precessions map the internal magnetic fields. For temperatures well below room temperature, ME-$\mu $SR analysis yields two unique frequencies ($\sim $1.8 MHz and $\sim $2.4 MHz) corresponding to two different magnetic field regions (13 mT and 18 mT ) probed by the muon. Previous studies [2, 3] using Fourier analysis and curve fitting have shown only one broad frequency signal. We seek to confirm our new improved findings through dipole field search calculations and ME-$\mu $SR simulations at these near-zero $\mu $SR frequencies. [1] JC Lee \textit{et al,} J Appl Phys 95 (2004) 6906; AIP/APS www: Virtual J Applications of Superconductivity, June 2004 V6 Iss11; S. Alves \textit{et al,} Phys Rev \textit{Rapid Comm }B49 (1994) 12396. [2] WK Dawson \textit{et al,} J Appl Phys 69 (1991) 5385. [3] DW Cooke \textit{et al}, Phys Rev B41 (1990) 4801.