Magnetic properties of 3D nanocomposites consisting of an opal matrix with embedded spinel ferrite particles

The magnetic properties of 3D nanocomposites representing Mn–Zn, Ni–Zn, Co–Zn, La–Co–Zn, and Nd–Co–Zn spinel ferrite particles embedded in the interspherical spaces of opal matrices are studied. Experimental data are obtained in the temperature interval 2–300 K by measuring the magnetization at a static magnetic field strength of up to 50 kOe and the ac magnetic susceptibility at an alternating magnetic field amplitude of 4 kOe and a frequency of 80 Hz.