Following the Evolution of Spin Dynamics in the Quantum Spin Liquid Candidate, ZnCu3(OH)6FBr

Zn-doped barlowite, ZnxCu4-x(OH)6FBr, is a new experimental realisation of an S = 1/2 kagome antiferromagnet in which the ground state may be tuned from a Néel ordered state to a quantum spin liquid phase upon separation of the Cu2+-based kagome layers with diamagnetic Zn2+ ions. We have previously explored the doping phase diagram of barlowite on MuSR on a range of samples up to x = 0.66. Now, we have established a new synthesis procedure that yields samples with x = 0.99. Thus, we request here further access to MuSR to complete our study and confirm ZnCu3(OH)6FBr as a quantum spin liquid candidate.