μSR study on the quasi-1D spin-1/2 quantum antiferromagnet NaVOPO4, close to the quantum critical point

We wish to carry out μSR experiments on a quasi-one-dimensional spin-1/2 antiferromagnet NaVOPO4. We have already studied the structural and magnetic properties of NaVOPO4 by means of x-ray diffraction, magnetic susceptibility, high-field magnetization, specific heat, and 31P nuclear magnetic resonance measurements. All our experimental results are well explained on the framework of 1D alternating spin chain model with a tiny spin gap. Interestingly, NaVOPO4 undergoes a field-induced quantum phase transition above a critical field of ~1.6 T. The H-T phase diagram resembles a dome type structure as reported in various quantum magnets undergoing Bose-Einstein condensation of triplons. The main objectives of our proposed μSR experiment are to search for magnetic long-range order down to 30 mK in zero field and to detect the field induced magnetic long-range order.