Nonlinear resonant and high dielectric loss behavior of CdS∕α-Fe2O3 heterostructure nanocomposites

Abstract

Cd S ∕ α - Fe 2 O 3 heterostructures, where the CdS nanorods grow irregularly on the side surface of α-Fe2O3 nanorods, were synthesized via a three-step process. The dielectric properties of the CdS∕α-Fe2O3 heterostructure nanocomposites have been investigated. The equivalent circuit model of the CdS∕α-Fe2O3 heterostructures was established, which reasonably explained the nonlinear dielectric resonant behavior of the CdS∕α-Fe2O3 heterostructure nanocomposites in the range of 5–15GHz. The high dielectric loss is mainly attributed to the conductance loss and the dipole relaxation loss in the CdS∕α-Fe2O3 heterostructures.

Facile solvothermal synthesis of novel hetero-structured CoNi–CuO composites with excellent microwave absorption performance

“…According to those previous reports, 38-40 the dielectric resonances at 3.6 GHz should be related with CoNi particles. However, the hetero-junction capacitance generated at the interface of CuO nanoakes and CoNi alloy microspheres could induce the other two resonant peaks (9.8 and 15.4 GHz), which were similar to previous reports by Shi, 38 Liu 39 and Lv.…”

Enhanced microwave absorption capabilities of Ni microspheres after coating with SnO2 nanoparticles

“…Three peaks can also be observed near the resonant frequencies on the e 00 curve. These phenomena are the typical characteristics of nonlinear resonant behaviors [33]. The nonlinear dielectric resonance originates mainly from the cooperative consequence of the Ni cores, the core/shell interfaces and the dielectric SnO 2 shells [15].…”

Synthesis, characterization and microwave absorption of carbon-coated Cu nanocapsules

“…Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) images were obtained on a JEOL JEM-2010 transmission electron microscope at an acceleration voltage of 200 kV. The paraffin-Cu nanocapsules composite was prepared by uniformly mixing Cu nanocapsules with paraffin, as described in detail elsewhere [2][3][4][5][6][7][8][9][10][16][17][18][19][20] , by homogeneously mixing the nanocapsule with paraffin and pressing them into cylindershaped compacts. Then the compact was cut into toroidal shape with 7.00 mm outer diameter and 3.04 mm inner diameter.…”

“…In recent years, with the development of local electronic devices, microwave communication, and the rising pollution of electromagnetic (EM) interference, materials with EM-wave absorption in a wide frequency range, with strong absorption, low density, and low cost are more and more desirable 3 . The EM-wave absorption properties of magnetic material-based nanocomposites and heterostructured nanocomposites have been intensely investigated, because of the synergetic effect between magnetic and dielectric losses [4][5][6][7] . Among the candidates for EM-wave absorbers, magnetic nanocapsules with carbon as shells have attracted intensive interest on account of the following facts: (1) the large saturation magnetization and high Snoek limit, (2) the suppression of the eddy current phenomenon, and (3) being composites with different kinds of EM-absorber materials 8 .…”