Effect of Zn doping on the phase transition temperatures of Ni$_{3}$V$_{2}$O$_{8}$

There is a considerable interest in understanding the nature of magnetic phase transition in geometrically frustrated materials. Ni$_{3}$V$_{2}$O$_{8}$ is one such system, with spin-1 Ni$^{2+}$ ions forming a layered buckled Kagome structure. We have studied the effects of doping spin-0 Zn ions on the magnetic phase transitions of powder Ni$_{3}$V$_{2}$O$_{8}$ using dielectric and heat capacity measurements. (Ni$_{1-x}$Zn$_{x})_{3}$V$_{2}$O$_{8}$ powder samples were synthesized starting with a mixture of Ni, V and Zn metal organic solutions mixed at appropriate atomic ratio. XRD and Raman studies show that (Ni$_{1-x}$Zn$_{x})_{3}$V$_{2}$O$_{8}$ powder samples annealed at 1000$^{\circ}$C crystallize in Ni$_{3}$V$_{2}$O$_{8}$ structure without forming any secondary phases. We have observed from heat capacity measurements that the phase transitions T$_{H}$, T$_{L,}$ and T$_{C}$ at 9.2K, 6.4K, and 3.9K expected for Ni$_{3}$V$_{2}$O$_{8}$ are present in our (Ni$_{1-x}$Zn$_{x})_{3}$V$_{2}$O$_{8}$ samples up to a Zn concentration of 20{\%}. The transition at 2.4 K was not clearly observed. All three transitions shift toward lower temperatures with an increase in Zn concentration. We will present the experimental results on the strong suppression of both T$_{H}$ and T$_{L}$ due to dilution of Ni$_{3}$V$_{2}$O$_{8}$ with non-magnetic Zn. Furthermore, we will present a quantitative comparison of this suppression with the 2D Ising and Heisenberg models.