Structure, magnetism, and transport of single-crystalline RNiSi3(R = Y, Gd-Tm, Lu)

Abstract

We report on the physical properties of the intermetallic series $R{\mathrm{NiSi}}_{3}\phantom{\rule{4pt}{0ex}}(R=\text{Y}$, Gd-Tm, Lu). High quality single crystals with platelike morphology were grown using the Sn flux method. X-ray powder diffraction data show that this series crystallizes in the orthorhombic space group Cmmm, and Laue patterns indicate that the b axis remains perpendicular to the plane of the plates. Magnetization measurements show anisotropic antiferromagnetic ground states for $R$ = Gd-Tm with N\'eel temperatures ranging from ${T}_{N}=2.6$ K $({\mathrm{TmNiSi}}_{3})$ up to 32.2 K $({\mathrm{TbNiSi}}_{3})$, as well as metamagnetic transitions that in some cases appear together with hysteresis $({\mathrm{TbNiSi}}_{3},{\mathrm{DyNiSi}}_{3}$, and ${\mathrm{HoNiSi}}_{3})$. The easy axis changes from a axis to b axis on going from $R$ = Gd-Ho to $R$ = Er-Tm. All transitions from antiferromagnetic to paramagnetic states are clearly marked by sharp peaks in specific heat as well as in the derivative of resistivity measurements, which show metallic temperature dependence for all compounds and residual values in the range of $1\ensuremath{\mu}\mathrm{\ensuremath{\Omega}}\phantom{\rule{0.16em}{0ex}}\mathrm{cm}$. ${\mathrm{DyNiSi}}_{3}$ has two close phase transitions, while ${\mathrm{HoNiSi}}_{3}$ presents distinct critical temperatures for applied fields in the $a$ or $c$ directions (10.4 and 6.3 K, respectively), pointing to possible component-specific ordering of the local magnetic moments.