Magnetic and dielectric properties of bismuth-containing high-entropy garnet ferrites

Yttrium iron garnet (YIG) ferrite is extensively utilized in microwave devices due to its exceptional fundamental electromagnetic properties and easily adjustable magnetic properties. In recent years, there has been a growing interest in investigating high-entropy garnets. However, its dielectric properties have not been extensively studied. This study prepared a series of bismuth-containing high-entropy yttrium iron garnet ferrites (Bi 0.6 Gd 0.6 Ho 0.6 Y 0.6 Re 0.6 ) Fe 5 O 12 (Re = Dy, Er, Tm, Yb) using the solid-phase reaction method. The addition of Bi 3+ to the high-entropy matrix resulted in a reduction of the optimal phase forming temperature of garnet from 1450°C to 1150°C. Despite the incorporation of Bi 3+ with a relatively large ionic radius, no heterophase generation occurred, leading to the formation of a single garnet phase. These high-entropy garnet samples exhibited unique magnetic properties along with high dielectric constants and low dielectric losses. Specifically, the dielectric constant (ε') of sample HEYIG-4 is measured at 20.26, with a low dielectric loss of just 2.78 × 10 −3 , while the specific saturation magnetization reached 16.86 emu/g. This paper expanded research within the field of high-entropy garnet ferrites.