Magnetism in Ytterbium-Based spin-½ Triangular-Lattice Delafossites

Ytterbium (Yb)-based delafossites with an effective S=1/2 have garnered significant attention in the condensed matter community due to their potential to stabilize quantum spin liquid (QSL) ground states. In this work, we have synthesized two novel Yb-based triangular-lattice delafossites. We investigated these systems using magnetization, heat capacity, and neutron diffraction measurements. One system exhibits antiferromagnetic long-range ordering around 2.7 K, while the other shows no magnetic ordering down to low temperature. Based on these measurements, we have constructed the magnetic phase diagram. We will present detailed discussions on the magnetic phase transitions and the behavior of these systems under applied magnetic fields.