Temperature dependent⁸⁹Y NMR study on multiferroic YCrO₃

In this manuscript, we report the⁸⁹Y NMR measurement as a function of temperature on single phase and pure polycrystalline YCrO₃sample to study the magnetism and relaxation times on a microscopic level across the magnetic transition (T_N≃ 141 K) from paramagnetic to antiferromagnetic state. The NMR peak width broadens abruptly upon crossingT_Ndue to the onset of internal magnetic fields, while peakshift slight decreases. A slight increase and subsequent anomalous decrease in the NMR peak intensity is observed on approachingT_Nfrom 300 K. There is also a significant increase in peak width. The temperature dependence of the⁸⁹Y NMR spin-lattice relaxation rates 1/T₁indicates a phase transition atT_Nwhich is of magnetic origin due to Cr³⁺ions, with an anomalously rise of fluctuations belowT_N. AboveT_N, this spin-lattice relaxation rate can be fitted to a power-law scaling behavior 1/T₁∼Twith an exponent factorβ≈ 0.8, indicates low energy spin fluctuations. Moreover, Knight shift and 1/TT₁scales linear with the bulk susceptibility which suggests the antiferromagnetic spin fluctuation in the YCrO₃system.