A μμSR study of the metamagnetic phase transition in the electron-transfer salt [FeCp2*][TCNQ]

We have used muon-spin rotation (μμSR) to study the metamagnetic transition in [FeCp2*][TCNQ] where Cp*=C5Me5Cp*=C5Me5 and TCNQ is 7,7,8,8-tetracyano-p-quinodimethane. This electron-transfer salt contains parallel chains of alternating [FeCp2*]+ cations and [TCNQ]-[TCNQ]- anions. Our zero-field μμSR data show the 2.5 K transition and show that a static, but disordered, internal field distribution develops below this. High-transverse-field μμSR has also been used to study the metamagnetic transition and the data illustrate how the internal field distribution changes through this transition.