The magnetic phase diagram of $\mathrm{N}{\mathrm{i}}_{1-x}\mathrm{Z}{\mathrm{n}}_x\mathrm{C}{\mathrm{r}}_2{\mathrm{O}}_4$ demonstrates complex magnetic transitions for $x=0.05$ with two long-range magnetic-order transitions at ${T_C}_1=41\mathrm{K}$ and ${T_C}_2=17\mathrm{K}$. A glasslike feature emerges between ${T_C}_1$ and ${T_C}_2$ with the application of a direct current (dc) magnetic field in alternating current (ac) susceptibility measurements. Dielectric measurements show a change from the conventional dielectric to a quantum-paraelectric-like behavior without anomalies near the magnetic ordering temperature in the range $0.05<x\le 1$. The strong correlation among magnetic, dielectric, and ferroelectric properties near the structural relaxation temperatures 41 and 17 K confirms the emergence of multiferroic behavior in $\mathrm{N}{\mathrm{i}}_{0.95}\mathrm{Z}{\mathrm{n}}_{0.05}\mathrm{C}{\mathrm{r}}_2{\mathrm{O}}_4$. A significant x-ray magnetic circular dichroism signal at the Ni site and ac susceptibility measurements indicate a spin-canting behavior between ${T_C}_1$ and ${T_C}_2$. The dilute doping of the non-Jahn-Teller Zn ion in the Jahn-Teller Ni site modulate the different magnetic exchange interactions of Ni and Cr, which could invoke spin-canting and multiferroic behaviors.

• Received 22 July 2016
• Revised 22 October 2016

DOI:https://doi.org/10.1103/PhysRevB.94.205143