Crystal Growth and anisotropic magneto-transport properties of semimetallic LaNiSb3

Abstract

Single crystals of LaNiSb$_3$ were grown using the Sn flux method. Structural characterization confirms that LaNiSb$_3$ crystallizes in the orthorhombic $Pbcm$ space group with lattice parameters $a = 13.0970(2)\,\mathrmÅ$, $b = 6.1400(4)\,\mathrmÅ$, and $c = 12.1270(4)\,\mathrmÅ$. Electrical resistivity measurements demonstrate metallic behavior over the entire temperature range of 3--300~K. The magnetoresistance exhibits a positive anisotropic response, attaining a maximum of $\sim 8\%$ for $H \parallel b$, with a pronounced crossover from quadratic to nearly linear field dependence. Angular-dependent MR measurements reveal a pronounced twofold symmetry upon magnetic field rotation within both the $ab$ and $ac$ crystallographic planes up to 50~K, indicating anisotropic charge transport. Hall resistivity measurements show predominantly electron-type conduction at high temperatures, with an increasing hole contribution upon cooling. The multiband character is further corroborated by the violation of Kohler's scaling and is well described within a semiclassical two-band framework. Collectively, these results suggest that LaNiSb$_3$ exhibits anisotropic multiband electronic transport and is a compelling candidate for exploring structure--property correlations in topological semimetals.

Figures (5)

• Figure 1: (a) Powder X-ray diffraction pattern of LaNiSb$_3$ single crystal. (b) Crystal structure of LaNiSb$_3$ (c) Energy-dispersive X-ray (EDX) elemental spectrum of LaNiSb$_3$.
• Figure 2: Temperature dependence of the electrical resistivity, $\rho(T)$, for current applied along the $b$ axis. (a) Zero-field resistivity for the configuration $I \parallel b$. (b) $\rho(T)$ measured under applied magnetic fields of 0, 5, and 9 T with $H \parallel a$. (c) Bloch--Grüneisen (BG) fitting of the resistivity data for $I \parallel b$ and $H \parallel c$ in the temperature range 3--300 K. (d) Comparison of the resistivity fits using the power-law relation $\rho(T)=\rho(0)+AT^{\alpha}$ and the BG model. The inset highlights the $\rho(T)$ behavior at higher magnetic fields.
• Figure 3: Magnetoresistance (MR) under different field--current configurations. (a) MR as a function of magnetic field $H$ at 3 K for $I \parallel b, H \parallel a$; $I \parallel b, H \parallel b$; and $I \parallel b, H \parallel c$. The solid green line represents linear fit for the $H \parallel a$ configuration. The MR follows a power-law dependence $\sim H^{n}$ with the fitted exponents indicated in the panel. (b) MR versus $H$ for $I \parallel b, H \parallel a$ measured from 3 K to 300 K. (c) Kohler’s plot of MR as a function of $H/\rho_{0}$ for $I \parallel b, H \parallel a$. (d) MR versus $H$ for $I \parallel b, H \parallel b$ at selected temperatures (3, 10, and 20 K), inset shows corresponding Kohler's plot. (e) MR versus $H$ for $I \parallel b, H \parallel c$ at temperatures between 2 K and 50 K. (f) Kohler’s plot of MR versus $H/\rho_{0}$ for $I \parallel b, H \parallel c$.
• Figure 4: Angular magnetoresistance: (a) Schematic illustration of the measurement geometry. The electric current is applied along the $b$ axis ($I \parallel b$). The polar angle $\theta$ is defined for rotation of the magnetic field in the $ab$ plane ($H \parallel ab$), while $\phi$ corresponds to rotation in the $ac$ plane ($H \parallel ac$). (b) Angular dependence of resistance $R(\theta)$ measured at 9 T for $I \parallel b$, $H \parallel ab$ at different temperatures (3--50 K). Solid lines represent fits to the data with equation 3. (c) Normalized resistivity $R_\phi/R_0$ as a function of $\phi$ at 9 T for $I \parallel b$, $H \parallel ac$ at various temperatures. (d) Temperature dependence of the anisotropic magnetoresistance (AMR) ratio extracted for $I \parallel b$, $H \parallel ab$.
• Figure 5: Hall effect analysis and two-band model fitting: Field dependence of Hall resistivity $\rho_{xy}$ at (a) Higher temperatures (30--300 K). Solid lines represent fits using the semiclassical two-band model. (b) $\rho_{xy}(H)$ measured at low temperatures (3--15 K) together with two-band model fits. (c) Temperature dependence of the carrier mobilities $\mu_e$ (black symbols) and $\mu_h$ (red symbols) extracted from the two-band fitting. Inset: Temperature dependence of the electron and hole carrier densities ($n_e$ and $n_h$).