Spin glass behavior in the weberite related structure Dy$_{\mathrm{3-x}}$Y$_{\mathrm{x}}$TaO$_{7}$

Crystalline structures with tetrahedral arrangement of magnetic cations are susceptible to present non-collinear magnetism. Dy$_{3}$TaO$_{7}$ with weberite-type crystal structure has this arrangement and could display non-conventional magnetic coupling. Previous magnetic studies on Dy$_{3}$TaO$_{7}$ have characterized this as an antiferromagnetic system with T$_{\mathrm{N}}$ of about 3 K. In this work magnetic properties of polycrystalline samples of the Dy$_{\mathrm{3-x}}$Y$_{\mathrm{x}}$TaO$_{7}$, with weberite structure are presented. X-Ray diffraction of our samples are single phase in all range of compositions. Magnetic properties measured from 2 - 300 K shown a typical Curie-Weiss behavior with the Dy$^{3+}$ effective magnetic moment about 10.35 $\mu_{\mathrm{B}}$. The compositions x$=$0.66, 0.33, and 0.0 display a maximum in the susceptibility \textit{vs.} temperature at 2.3, 2.7, and 3 K respectively. This behavior has been previously assigned to an antiferromagnetic transition; however our AC magnetic measurements as a function of frequency indicate a spin glass behavior. Since magnetic cations have tetrahedral arrangement for x$=$0, a magnetic frustrated state is anticipated for this composition.