Electrical and Magnetic Properties Modification in Heavy Ion Irradiated Nanograin Ni_xCo_(3–x)O₄ Films

Abstract

Reactively sputtered Ni x Co (3−x) O 4 films (x = 1.5, 1.0, and 0.75) were grown and subsequently irradiated with 5.5 MeV Si + ions to investigate effects of lattice-site and charge state distribution. Films were characterized before and after irradiation by X-ray diffraction, X-ray photoemission spectroscopy, Rutherford backscattering spectroscopy, electric resistivity measurements, and temperature-dependent AC and DC magnetometry. Results indicate that ion irradiation induces oxygen loss, partial reduction of nickel, and an increase in both low-temperature ferrimagnetism and room-temperature conductivity. Frequency-dependent AC magnetic susceptibility measurements indicate a spin-glass-like transition at low temperature which moves to higher temperature after irradiation. Significance of the charge transfer for magnetism and conduction in a mixed spinel with Co 2+ , Co 3+ , Ni 2+ , and Ni 3+ in tetrahedral and octahedral sites is discussed.

Inkjet Printing as High-Throughput Technique for the Fabrication of NiCo2O4 Films

“…Since the binding energies of Co 3+ (779.4 eV) and Co 2+ (780.8 eV) are very close, the presence of satellite peaks is very important in order to determine the oxidation states of cobalt. In this respect, the observed satellites at 785 and 802 eV can be assigned to the presence of Co 2+ ions [8]. On the other hand, the nickel 2p spectrum contains peaks associated with 2p3/2 (854 eV) and 2p1/2 (872 eV) as well as their respective satellite peaks at 861 and 880 eV.…”

“…NiCo 2 O 4 oxide has recently been a motivating topic from the viewpoint of materials science because of its interesting catalytic, electrical, and optical properties. These properties are related to important technological applications such as electrodes for fuel cells [1,2], electrodes in sodiumand lithium-ion batteries [2][3][4], optoelectronic [5,6] and magnetic devices [7,8], supercapacitors [4,[9][10][11][12][13], flat-panel displays [2,14], infrared transparent conducting materials [2,5,14], glucose sensors [15], and several electrochemical reactions [1,6,7,[16][17][18][19][20]. In particular, the production of clean energy from renewable sources as in the electrocatalytic water splitting process is an attractive alternative for an energy economy based on hydrogen [20,21].…”

“…Many of the above-mentioned applications of NiCo 2 O 4 require its fabrication in thin film form; moreover, taking into consideration a possible scale-up, the surface dimensions of the film is an important issue. In this respect, NiCo 2 O 4 films have been principally prepared by physical deposition processes such as pulsed laser deposition [16,[23][24][25] and radio frequency magnetron sputtering [5,8], as well as by means of chemical routes including electrodeposition [6,14,15], sol-gel [2], hydrothermal synthesis [26], spray pyrolysis [4], and chemical vapor deposition [27]. In general, if cost of the process and equipment requirements are considered, the solution-based chemical methods are more appropriate than physical routes.…”

Synthesis of Zinc - Bismuth Complex Oxide and Experimental Analysis of Its Magnetic and Electrical Characteristics

“…With the different options, we can measure the magnetic properties and electrical transport properties as we need [3] [9]. In addition, the system can provide the ultra-low temperature (1.9K), and the use of immersion in liquid helium in the superconducting excitation can produce a strong magnetic field (± 9T).…”

“…They can be applied to many aspects, such as catalysts, electrolyte materials, optoelectronic materials, electronic ceramic powder materials, high temperature superconducting materials. In addition, they can also be applied in other materials such as nuclear waste materials, absorbing materials, in which these complex oxide crystals also have a good application prospects [2] [3]. Therefore, the formation mechanism of dendrites has attracted much attention for a long time, and most of them have been focused on the fractal research.…”