We report the structural and magnetic properties of pure nanoparticles (NPs) and graphite (G)-modified nano composites (NCs): G, CuO, Fe2O3, CuFe, Cu/G, Fe/G, and CuFe/G. XRD confirmed the formation of hexagonal, monoclinic, rhombohedral, and mixed structures. Magnetic characterization revealed that while G exhibits ferromagnetism (FM) alongside diamagnetism, the NPs and NCs display a complex mix of FM, antiferromagnetic (AFM), and paramagnetic behaviors. A key finding is that adding G to NPs modulates the saturated magneti zation (Ms), increasing it for Cu/G to 0.205 emu/g at 300 K but decreasing it for Fe/G and CuFe/G to approx imately 0.30 emu/g. Notably, the Ms for CuO NPs dramatically increased from 0.090 emu/g at 300 K to 0.827 emu/g at 10 K. Furthermore, the materials’ magnetic hardness was tunable: Fe2O3 NPs and Fe/G NCs were hard magnetic materials at 300 K with coercive fields (Hc) of 739 Oe and 344 Oe, respectively, while CuO NPs and CuFe/G NCs became hard magnetic at 10 K with Hc values of 8459 Oe and 448 Oe. The field-cooled and zero- field-cooled magnetization curves confirmed superparamagnetic behavior with blocking temperatures (Tb) ranging from 200 K to 260 K. A N´ eel temperature (TN) of ~230 K was identified in Fe-containing samples, indicating AFM ordering. The switching field distribution (SFD) was single-peaked at 300 K but showed a double peak at 10 K for CuO, CuFe, and CuFe/G. These findings demonstrate that the investigated NPs and NCs, with their tunable magnetic properties, hold significant potential for applications in magnetic storage, spintronics, and magnetic hyperthermia.