$gamma$-CoV$_{2}$O$_{6}$ is a quasi one-dimensional spin-$frac{3}{2}$ magnet that possesses two distinct magnetic orders in the ground state with modulation vectors $k_mathrm{1}$ = ($frac{1}{2}$, 0, 0) and $k_mathrm{2}$ = ($frac{1}{4}$, 0, -$frac{1}{4}$), respectively. Here, we use muon spin relaxation and rotation to reveal the thermodynamics of the magnetic phase separation in this compound. In the paramagnetic (PM) region, short-range correlated spin clusters emerge at $T_mathrm{m}$ $simeq$ 26 K at the $it{partial}$ expense of the PM volume. Upon further cooling, we show that these emergent clusters become spatially coherent at $T_mathrm{{N2}}$ = 7.5 K and eventually form the $k_mathrm{2}$ order at $T^{star}$ = 5.6 K, while the remaining PM spins are driven into the $k_mathrm{1}$ state at $T_mathrm{{N1}}$ = 6.6 K. These results stress magnetic microphase inhomogeneity as a thermodynamic precursor for the ground state phase separation in weakly coupled spin-$frac{3}{2}$ chains.
تحميل البحث