Verification of long-range antiferromagnetic ordering in organic antiferromagnets lambda-D2GaCl4 (D=ET, BEST) using pulsed muSR

The organic superconductor lambda-(BETS)2GaCl4 shows unconventional superconducting properties. To investigate the mechanism of superconductivity, we have studied the antiferromagnetic insulating phase near the superconducting phase. We recently performed the muSR experiment in PSI on lambda-D2GaCl4 (D = ET, BEST). The former shows antiferromagnetic ordering below 13 K revealed by NMR, but no clear muon precession signal was observed. This might be due to a small internal field at the muon site for this material, whereas a phase separation scenario could be expected in both materials. To reveal this possibility, we propose the muSR study of lambda-D2GaCl4 (D = ET, BEST) using pulsed muon source in ISIS facility, This experiment will give us to clarify the nature of the adjacent antiferromagnetic phase.