Nanostructured Zn-Substituted Nickel Ferrite Thin Films: CMOS-Compatible Deposition and Excellent Soft Magnetic Properties

The impact of solvent tanδ on the magnetic characteristics of nanostructured NiZn-ferrite film deposited by microwave-assisted solvothermal technique

“…Ni(II)acac, Zn(II)acac and Fe(III)acac were used as precursors (0.5:0.5:2 molar ratio; acac=acetylacetonate), and AR-grade ethanol (EA), 1-decanol (D), and benzyl alcohol (BA) were used as solvents to prepare various reaction mixtures (volume ratio of EA:D=3:5 (ED35), EA:D=3:3 (ED33), EA:BA=2:5 (EB25), EA:BA=3:5 (EB35), and EA:BA=3:3 (EB33), with ED35 reported earlier. 10 The tanδ (= ε ′′ r /ε ′ r ) of each solution was measured at 300 K at 2.45 GHz (the operating frequency of the microwave reactor used in MAS-D process) by a coaxial dielectric probe kit (Performance Probe, Keysight Inc.) connected to a vector network analyser and is tabulated in Table I. NZF films were deposited on a 1 cm × 1 cm Si (100) by exposing 10 ml of each reaction mixture with a constant microwave power (300 W) for 30 mins.…”

“…[4][5][6][7][8] Recently, we have developed a CMOS-compatible, low temperature Microwave-Assisted Solvothermal Deposition (MAS-D) process for various spinel ferrites and demonstrated its capability to yield smooth, uniform films with desired crystallite size. [9][10][11] For example, a soft magnetic NZF thin film was successfully synthesized using ethanol:1-decanol as solvent, and its structural and magnetic properties thoroughly characterized. 10 At 2.45 GHz, the timescale over which the field oscillates is about the same as the relaxation time (τ) of permanent dipoles in most organic and inorganic molecules.…”

“…[9][10][11] For example, a soft magnetic NZF thin film was successfully synthesized using ethanol:1-decanol as solvent, and its structural and magnetic properties thoroughly characterized. 10 At 2.45 GHz, the timescale over which the field oscillates is about the same as the relaxation time (τ) of permanent dipoles in most organic and inorganic molecules. So, strongly polarizable solvents are particularly advantageous for rapid heating in MAS-D.…”

Strain induced anisotropy in liquid phase epitaxy grown nickel ferrite on magnesium gallate substrates

“…It is however possible to achieve a significant modification of magnetic parameters in thin films. A variety of techniques were used in the past to synthesize films of NFO, including electrodeposition 22 , chemical vapor deposition 23 , microwave-assisted solvothermal process 24 , pulsed laser deposition (PLD) 25 – 29 , and liquid phase epitaxy (LPE) 30 , 31 . The objective in most of the past studies was to take advantage of strain due to film-substrate lattice mismatch to achieve a large growth induced anisotropy field.…”

Resonance frequency above 20 GHz in superparamagnetic NiZn-ferrite

“…Nanocrystalline spinel ferrite thin films deposited by lowtemperature (<200 C) microwave-irradiation-assisted solvothermal (MAS) deposition comprise densely packed superparamagnetic particles, which exhibit the "far-from-equilibrium" distribution of cations in their crystal structure that is unique to MAS deposition. 21,22 Owing to the superparamagnetic property and out-of-place cations, the high frequency resonance characteristics of MAS deposited films are expected to exhibit both precession and relaxation mechanisms. In this context, high-frequency magnetic characteristics of the superparamagnetic NZF thin films deposited by the MAS process are investigated here.…”