“…To date, composites of the above materials are the ideal candidates in EM wave absorbing and shielding fields, such as (100-x)La 1.5 Sr 0.5 NiO 4 /xNiFe 2 Hexaferrites, classified into M-, W-, Y-, Z-, X-and U-type according to their chemical formulas and structures, have been widely used in microwave and millimeter wave devices as permanent magnets or gyromagnetic materials, e.g., in circulators, filters, isolators, inductors, and phase shifters [16][17][18][19] . Z-type hexagonal barium ferrites (Co 2 Z) with hexagonal planar structure can be applied in the gigahertz region due to their significant permeability, relatively high frequency response, strong magnetocrystalline anisotropy field and high cut-off frequency [20][21][22] . Some work M A N U S C R I P T…”