Structural, magnetic and impedance dynamics of multiferroic high entropy garnet ceramics.

We have synthesized (G d 0.2 Y 0.2 N d 0.2 D y 0.2 R 0.2) 3 F e 5 O 12 (R = E r , S m and Pr) high entropy garnet ceramic samples via solid-state reaction route for the first time. All the samples are formed in a single phase and exhibit a simple cubic crystal structure with an I a 3 ‾ d space group. The lattice constant of these samples varies as per the ionic radii of the substituted element and ranges in between 12.4458 Å to 12.5062 Å. The morphology and elemental contributions are also investigated for all the high entropy samples. Additionally, magnetization data reveal a similar value of room temperature saturation magnetization i.e., ∼ 16 e m u / g for (G d 0.2 Y 0.2 N d 0.2 D y 0.2 R 0.2) 3 F e 5 O 12 (R = S m and Pr) samples and it becomes 13.67 e m u / g for Er doped sample. This variation is understood with Dionne's sublattice magnetization model where the molecular weight of the substituent will affect the saturation magnetization. Furthermore, a deviation from ideal Debye-type relaxation behavior is noticed in room temperature Nyquist plots for all three samples. An anomaly in the dielectric plot around ferrimagnetic transition temperature indicates the multiferroic behavior of these high entropy ceramic materials. [ABSTRACT FROM AUTHOR]