Transport properties of Ho_1−x Lu _x B₁₂ solid solutions

Abstract

Our studies of Ho_1−x Lu _x B₁₂ solid solutions have shown that the temperature of antiferromagnetic (AF) order in geometrically frustrated system of HoB₁₂ (T _N = 7.4 K) is linearly suppressed to zero temperature, i.e. T _N → 0, as lutetium concentration increases to x→x _c ≈ 0.9. In this contribution, we present original results of electrical resistivity measurements on Ho_1−x Lu _x B₁₂ single crystalline samples with x = 0, 0.2, 0.5, 0.7, 0.9, 1 in the temperature range 0.06–300 K and in magnetic fields (B) up to 8 T. Complex B vs T _N phase diagrams were received from precise temperature ρ(T) and field ρ(B) dependences of resistivity with several AF phases for x ≤ 0.5 pointing to a possibility of quantum critical point at x _c ≈ 0.9. The scattering of conduction electrons in the AF phase and in the paramagnetic phase as well as Hall effect results are analyzed and discussed for various concentrations x, when magnetic dilution increases with the increasing content of nonmagnetic Lu ions in the Ho_1−x Lu _x B₁₂ system.