Microporous networks of NiMn₂O₄ as a potent cathode material for electric field emission

Abstract

The electric field-induced sterling electron emission of NiMn2O4 microporous networks synthesized via the sol-gel auto combustion route was investigated. Some primary characterization techniques such as x-ray diffraction, Fourier-transform infrared spectroscopy, and Raman spectroscopy were performed to confirm the pure crystallinity and metal oxide (Ni–O and Cr–O) stretching vibrations and also to provide a molecular fingerprint of the NiMn2O4 porous network. The distinct field emission (FE) properties of the NiMn2O4 microporous network was observed which was correlated with an electric field induced electron tunneling F–N (Fowler–Nordheim) model from a nearly planner conducting emitter surface with triangular potential-energy barrier approximation. A low turn-on field of 4.15 V µm−1 and threshold field of 5.25 V µm−1 were detected to draw emission current densities of 1 µA cm−2 and 10 µA cm−2 respectively. The local work function (Φ) of 5.509 eV for the NiMn2O4 porous network was computed using density functional theory (DFT) and it exhibits an impressive field enhancement factor (β) of 3381 with good FE current stability. These results demonstrate the potential application of this material for future vacuum micro/nanoelectronics and FE panel display applications.

Low-Temperature Spin-Canted Magnetism and Bipolaron Freezing Electrical Transition in Potential Electron Field Emitter NdNiO3

“…This channel-like morphology is advantageous for productive field emission properties. 39 Figure 1e shows the FESEM micrographs of as-sintered samples for the dielectric and magnetic study, and the grain growth is confirmed in the nm range 2a] additionally confirm the average particle sizes of NdNiO 3 below 100 nm with weak agglomeration. Nanoparticles influence distinctively its magnetic and electrical transport properties compared to its bulk counterparts.…”

“…The tiny peaks at 481 and 489 cm –1 (pinpointed in Figure b with black arrows) are associated with Nd–O–Ni and Ni–O–Nd coupling vibrations, which further reinforced the strong bonding between atoms in the orthorhombic system. , The surface morphology of NdNiO 3 used for the field emission study is displayed in Figure c,d, and it exposed microporous network-like images with an enriched conducting channel. This channel-like morphology is advantageous for productive field emission properties Figure e shows the FESEM micrographs of as-sintered samples for the dielectric and magnetic study, and the grain growth is confirmed in the nm range between 60 and 105 nm with average particle sizes ∼95 nm.…”

“…The maximum entropy mapping (MEM) in Figure c displays the three-dimensional (3D) electron/nuclear density map from XRD powder diffraction data by maximizing the entropy ( S ) information under some constraints . MEM of electron density provides us information about electron richness of field emission measurements along any sharp hkl planes (Miller indices), and it was obtained by using , and where ρ k is the normalized density at r k positions and from the previous iteration in 3D gridded space; τ k is the density derived from prior information; and N is the total number of pixels in the unit cell. We have used the Hubbard U = 4.9 eV for d-orbital of Ni atom to consider on-site Coulombic repulsion.…”

“…The maximum entropy mapping (MEM) in Figure 5c displays the three-dimensional (3D) electron/nuclear density map from XRD powder diffraction data by maximizing the entropy (S) information under some constraints. 56 MEM of electron density provides us information about electron richness of field emission measurements along any sharp hkl planes (Miller indices), and it was obtained by using 39,57…”

Fowler–Nordheim Law Correlated with Improved Field Emission in Self‐Assembled NiCr2O4 Nanosheets

“…This implies that the FD distribution should be considered for calculation, which is a statistical function that provides the probability to discover an electron in a given electronic state. The work function was calculated using the described methods implemented in the Quantum Espresso code following the equationwhere E vac and E f are the electrostatic potential energy in a vacuum and Fermi energy.…”