Multiglass properties and magnetoelectric coupling in the uniaxial anisotropic spin-cluster-glassFe2TiO5

The compound ${\mathrm{Fe}}_{2}\mathrm{Ti}{\mathrm{O}}_{5}$ (FTO) is a well-known uniaxial anisotropic spin-glass insulator with two successive glassy freezing temperatures, i.e., transverse $({T}_{TF}=9\phantom{\rule{0.16em}{0ex}}\mathrm{K})$ and longitudinal $({T}_{LF}=55\phantom{\rule{0.16em}{0ex}}\mathrm{K})$. In this article, we present the results of measurements of complex dielectric behavior, electric polarization as a function of temperature $(T)$, in addition to characterization by magnetic susceptibility and heat capacity, primarily to explore magnetoelectric (ME) coupling and multiglass properties in uniaxial anisotropic spin-cluster-glass FTO. The existence of two magnetic transitions is reflected in the isothermal magnetodielectric (MD) behavior in the sense that the sign of MD is different in the $T$ regime $Tl{T}_{TF}$ and $Tg{T}_{TF}$. The data in addition provide evidence for the glassy dynamics of electric dipoles; interestingly, this occurs at much higher temperature (\ensuremath{\sim}100--150 K) than ${T}_{LF}$, with high remnant polarization at 10 K $(\ensuremath{\sim}4000\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{C}/{\mathrm{m}}^{2})$ attributable to short-range magnetic correlations, thereby offering a route to attain ME coupling above 77 K.