${\text{La}}_2{\text{Ni}}_7$ is an itinerant magnetic system with a small ordered moment of $\sim 0.1{\mu }_B/\text{Ni}$ and a series of antiferromagnetic (AFM) transitions at $T_1=61.0\mathrm{K}, T_2=56.5\mathrm{K}$, and $T_3=42.2\mathrm{K}$. $M\left(H\right)$, and $\rho \left(H\right)$ isotherms as well as constant field $M\left(T\right)$ and $\rho \left(T\right)$ measurements on single-crystalline samples manifest a complex, anisotropic $H\text{−}T$ phase diagram with multiple phase lines. Here we present the growth and characterization of single crystals of the ${\text{La}}_2{\text{(Cu}}_x{\text{Ni}}_{1-x}{)}_7$ series for 0 $\le x\le$ 0.181. We measured powder x-ray diffraction and composition, as well as anisotropic temperature- and field-dependent resistivity, temperature- and field-dependent magnetization, and temperature-dependent heat capacity on these single crystals. Using the measured data we infer a transition temperature-composition $\left(T\text{−}x\right)$ phase diagram for this system to study the evolution of the AFM ordering upon Cu substitution. For $0\le x\le 0.097$, the system remains magnetically ordered at base temperature with $x\le$ 0.012, showing signs of multiple AFM ordering temperatures. For the higher substitution levels $0.125\le x\le 0.181$, there are no signatures of magnetic ordering, but anomalous features in resistance and heat capacity data are observed which are consistent with the Kondo effect in this system. The intermediate $x=0.105$ sample lies between the magnetic ordered and the Kondo regime and is in the vicinity of the AFM quantum critical point (QCP). Thus, ${\text{La}}_2{\text{(Cu}}_x{\text{Ni}}_{1-x}{)}_7$ is an example of a small moment system that can be tuned through a QCP. Given these data combined with the fact that the ${\text{La}}_2{\text{Ni}}_7$ structure has kagomelike, Ni sublattices running perpendicular to the crystallographic $c$ axis, and a predicted $3d$-electron flat band that contributes to the density of states near the Fermi energy, ${\text{La}}_2{\text{(Cu}}_x{\text{Ni}}_{1-x}{)}_7$ becomes a promising system to host and study exotic physics.

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• Exotic phases of matter
• Flat bands
• Kondo effect
• Magnetic phase transitions
• Quantum phase transitions
• Antiferromagnets
• Single crystal materials
• Crystal growth
• Electrical transport techniques
• Magnetization measurements
• Specific heat measurements