Characterization of the Spin-Frustration in Doubly Ordered Perovskite NaYbZnWO$_6$ Obtained by High-Pressure Synthesis

We present the high-pressure synthesis of a novel doubly ordered perovskite NaYbZnWO$_6$ composed of the rare earth magnetic Yb$^{3+}$ ions and its comprehensive magnetic characterization. The structure consists of alternating layers of Yb$^{3+}$ and Na$^+$ ions along the c-axis, with Yb$^{3+}$ ions forming slightly distorted two-dimensional (2D) square lattices of kite-shape (Yb$^{3+}$)4 units. Low-temperature magnetic susceptibility measurements indicate that the ground state of Yb$^{3+}$ can be described by an effective J$_{eff}$ = 1/2 Kramers doublet. Further, specific heat analysis reveals an internal magnetic field of the order of 1.48 K; however, magnetization data do not exhibit magnetic ordering down to 0.4 K. The spin exchanges of NaYbZnWO$_6$ evaluated by density functional theory (DFT) calculations unveil spin frustration in the compound. These findings suggest that NaYbZnWO$_6$ is a promising candidate for realizing a magnetically disordered quantum state.