Metallic Ground Research Articles

Interplay of surface plasmon and Fabry-Perot resonances in metallic hole arrays on dielectric layers

This study investigates the resonant behavior of a nanostructured absorber consisting of a metal hole array (MHA) on a dielectric layer (BCB) forming a cavity on a metal ground plane (MGP). By varying the thickness of the BCB layer, the resonance spectra were analyzed under different conditions. Our simulations reveal the intricate interplay between surface plasmon and Fabry-Perot resonances within the MHA-BCB-MGP structure. We observe that as the dielectric thickness changes, the resonance peaks shift, exhibiting phenomena such as Rabi splitting and bifurcation. These features are particularly pronounced under transverse magnetic polarization, indicating the complex interaction between different resonance modes and polarization states. In addition, changes in MHA diameter affected the dominance of either surface plasmon or Fabry-Perot resonances, illustrating the complex relationship between structure and resonance behavior. Reflection spectra under different polarizations and angles of incidence showed agreement between simulation and experiment, validating the proposed model.

Enhanced edge - intrude triangle metamaterial absorber with polarization insensitivity for S, C, X and Ku band applications

This paper presents a novel metamaterial absorber designed to function effectively across the S, C, X, and Ku frequency bands (2–18 GHz). The unit cell of the metamaterial absorber is derived from an edge-intruded triangular structure, exhibiting multiple resonances. It is thoughtfully designed to achieve fourfold symmetry, ensuring polarization insensitivity. The proposed structure, fabricated on an FR4 substrate with a metallic ground plane, demonstrates exceptional absorption peaks at 2.5 GHz (97%), 3.4 GHz (96.5%), 5.2 GHz (99%), 9.07 GHz (98.8%), 12 GHz (98.1%), 13.66 GHz (89.1%), and 16 GHz (98.9%). The absorber’s four-fold symmetric design ensures polarization insensitivity, while its ultra-thin profile (0.013λ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\lambda$$\\end{document}) offers several practical benefits. By harnessing the unique properties of near-zero refractive index (NZRI) metamaterials, this absorber has the capability for precise control over electromagnetic waves. Its outstanding performance and versatility position it as a strong candidate for applications such as wavefront shaping, beam steering, sensing, and electromagnetic cloaking.

Multi-color long-wave infrared perfect absorber based on a heavily doped semiconductor that is inverse-designed via machine learning.

Metamaterial perfect absorbers (MPAs) with high absorption, thin thickness, and custom-tailorable spectrum are in great demand in many applications, especially in photoelectric detectors. Presently, infrared (IR) focal plane array detectors based on type-II superlattice (T2SL) still face the challenge of a low absorption coefficient. Moreover, it is still difficult to integrate conventional metal-insulator-metal (MIM) MPA with a T2SL infrared detector, due to the incompatibility of fabrication processes. In addition, the need to achieve custom-tailorable multi-peak absorption in the long-wave infrared band is high, and the design process of an MPA with a complicated geometric shape is time-consuming. To tackle these problems, in this work, we replace the ground metal layer in a conventional MIM MPA with a heavily doped semiconductor (n++), whose growth process is compatible with the fabrication process of T2SL infrared detectors and thus can be integrated with them. Moreover, we set up a deep neural network (DNN) to associate the spectral response of the device with the corresponding structural parameters. In this way, we can quickly inverse design the infrared perfect absorber with multiple absorption peaks using a trained DNN. The designed devices can achieve three perfect absorption peaks in the wavelength range of interest (8 ∼ 13 µm), and the peak absorptivity generally reaches over 90%. Our work provides an effective method for the inverse design of n++IM MPA based on DNN, which is of significant guidance for the study of infrared MPA. Additionally, our work anticipates enhancing the detection performance of infrared detectors through absorption enhancement, indicating substantial application potential in the field of optically modulated infrared detectors.

Robust Multi-Band DNG metamaterial absorber for GPS (L1), ISM, and 5G application with Enhanced polarization and angle stability

This research introduces a triple-band metamaterial absorber characterized by insensitivity to both polarization and incident angles. The structure includes square ring resonators on the upper side and a continuous metal ground on the lower side, separated by an FR4 substrate. At the lowest operating frequency, the unit cell’s thickness, and length measure 0.0128λ and 0.156λ, respectively. Under normal incidence, the proposed absorber demonstrates three clear absorption peaks at 1.56, 2.43, and 3.36 GHz, achieving absorption rates of 98 %, 99 %, and 97 %, respectively. The absorption response exhibits variation with incident angles up to 70° for both TM and TE polarizations due to its high-level symmetry. This configuration attains negative permittivity and permeability suitable for operational frequencies in the L-band and S-band. The study examines the electric field, impedance, and surface current to provide additional evidence for the absorption analysis. A validated RLC circuit equivalent to the proposed structure has been confirmed using Advanced Design System (ADS). The results indicate a slight deviation, especially at frequencies beyond the resonance frequencies. The structure underwent fabrication and testing in an anechoic chamber, revealing a strong correlation between the simulated and measured results. The suggested absorber holds promise for ISM applications, radar systems, sensing technologies, and energy harvesting systems.

Theoretical study of a triple-band tunable terahertz metamaterial absorber with polarization insensitive and high refractive index sensing based on bulk Dirac semimetal

In this paper, a triple-band metamaterial absorber in the terahertz frequencies is proposed, and its refractive index sensing characteristics are analyzed, where the bulk Dirac semimetal (BDS) periodic array is on top of a photonic crystal slab backed with a metal ground plane. The simulation results show that the absorber achieves three perfect absorption peaks in the range of 3.4–5.2 THz, whose absorption rates are over 96%, and a maximum quality factor (Q) of 74.1. The designed absorber exhibits excellent polarization insensitivity and dynamic tunability; further, the tuning of the Fermi energy level of BDS enables the dynamic adjustment of absorption frequencies and absorption rates of these peaks. By analyzing the distributions of the electromagnetic field and different structural parameters, it is revealed that the absorber mainly dissipates the electromagnetic wave through coupled resonance and localized surface plasmon resonance (LSPR) effects to achieve perfect absorption. Further, the metamaterial absorber shows the capacity to detect analytes with varying refractive indices, and the absorber has a maximum sensitivity S of 405 GHz/RIU with high detection accuracy. This work provides novel design options for triple-band terahertz metamaterial absorbers and their potential applications in refractive index sensing.

Experimental recurrence of an unreported fire risk of power cable: Discharge of bracket cable metallic grounding under coupled vibration conditions

In environments like bridges and tunnels, power cables are laid on metal brackets (hereinafter referred to as bracket cables). If the aluminum sheath and metal bracket form a metallic grounding fault, the air gap near the contact point may bear an intermittent discharge under the cable vibration, which is a potential source of cable fires. However, current research on cable grounding systems does not focus on analyzing the physical metallic grounding process. Discharge from coupled vibrations has been overlooked. This study accomplished the experimental recurrence of discharge at the metallic grounding point of cables under coupled vibration. According to the experimental observations, intermittent electric sparks and AC arc occur with the contact and separation of the aluminum sheath and the metal bracket due to vibrations. Under coupled vibration conditions, metallic grounding faults in cables pose a risk of causing cable fires.

Highly sensitive refractive index based biofuel adulteration sensor using multiband absorber

A multi-band electromagnetic absorber is proposed for sensing the adulterant concentration in biofuels based on refractive index variations at room temperature (300 K). The proposed absorber structure consists of a gold based metallic resonating geometry and metallic ground plane on the top and bottom layer of the cavity loaded dielectric material. The unit cell has volume of 24μm×24μm×3.57μm (0.1088λL×0.1088λL×0.01618λL where λL is wavelength at lowest operating frequency), five absorption peaks at 1.36, 3.349, 5.338, 5.887 & 9.307 THz with peak absorptivity of 96.15%, 97.55%, 95.63%, 83.60% & 96.13% and Full Width at Half Maxima (FWHM) of 0.098, 0.275, 1.01 & 0.417 THz respectively. For solid substrate, the absorption performance is polarization insensitive and with cavity inside the substrate, the absorption performance is polarization sensitive in normal incidence. The absorber’s Refractive Index (RI) and biofuel adulteration sensing performance is also analyzed by loading analyte on its top surface and inside the substrate cavity. Peak sensitivity of ∼3 THz/RIU with a maximum Figure of merit (FOM) of ∼5.69RIU−1 and maximum ∼0.16% error in ethanol based biofuel adulteration estimation are achieved. The proposed absorber has advantages of ultracompact dimensions, very high sensitivity and very less estimation error in adulteration estimation over other absorber based sensors.

Design and theoretical analysis of near-infrared multiband metamaterial absorber with concentric sub-resonators for solar applications

Metamaterial absorbers with multiple frequency bands can be designed by stacking sub-resonators vertically or arranging them co-planarly. However, to increase the number of absorption peaks, we often need more sub-resonators. Therefore, a study explores dynamic infrared multiband metamaterial absorbers to enhance electromagnetic wave absorption and addresses tunability challenges by utilizing a periodic sub-wavelength structure-based unit cell. The novel design comprises a concentric triangular strip within a central hollow of a square patch, with four hollow cylindrical spaces at the patch corners, each containing four small square pillars. The design comprises a metal–dielectric–metal architecture, with silver as the top patch and the ground metal layer separated by a thin magnesium fluoride dielectric layer. A temperature-controlled material vanadium dioxide layer is introduced below the upper metal layer to enhance the absorbance. Moreover, extensive parametric investigations have been conducted involving the manipulation of shape while keeping other dimensions constant. The goal is achieving perfect multiple absorptions within the 90–300 THz frequency range, ensuring impedance match and exhibiting plasmonic resonance characteristics. The study also investigates unit cell behavior regarding polarization and incident angle variations. Simulations are conducted using CST Microwave Studio Suite® with finite integration technology and validated with COMSOL Multiphysics® using the finite element method in the frequency domain. The simulated results reveal multiple absorption peaks in the terahertz range, averaging 98.32% with a maximum absorption of up to 99.99% and exhibiting high absorption coefficients at discrete resonance frequencies, suggesting promising applications in terahertz technology-related fields.

Sapphire-Based Optrode for Low Noise Neural Recording and Optogenetic Manipulation.

Electrophysiological recordings of neurons in deep brain regions using optogenetic stimulation are essential to understanding and regulating the role of complex neural activity in biological behavior and cognitive function. Optogenetic techniques have significantly advanced neuroscience research by enabling the optical manipulation of neural activities. Because of the significance of the technique, constant advancements in implantable optrodes that integrate optical stimulation with low-noise, large-scale electrophysiological recording are in demand to improve the spatiotemporal resolution for various experimental designs and future clinical applications. However, robust and easy-to-use neural optrodes that integrate neural recording arrays with high-intensity light emitting diodes (LEDs) are still lacking. Here, we propose a neural optrode based on Gallium Nitride (GaN) on sapphire technology, which integrates a high-intensity blue LED with a 5x2 recording array monolithically for simultaneous neural recording and optogenetic manipulation. To reduce the noise interference between the recording electrodes and the LED, which is in close physical proximity, three metal grounding interlayers were incorporated within the optrode, and their ability to reduce LED-induced artifacts during neural recording was confirmed through both electromagnetic simulations and experimental demonstrations. The capability of the sapphire optrode to record action potentials has been demonstrated by recording the firing of mitral/tuft cells in the olfactory bulbs of mice in vivo. Additionally, the elevation of action potential firing due to optogenetic stimulation observed using the sapphire probe in medial superior olive (MSO) neurons of the gerbil auditory brainstem confirms the capability of this sapphire optrode to precisely access neural activities in deep brain regions under complex experimental designs.

An ultra broadband metamaterial absorber based on metal-dielectric-metal technology for THz spectrum

This paper introduces a novel ultra-broadband Metamaterial Absorber (UBMA) demonstrating significant absorption capabilities across a wide terahertz frequency range from 2.42 THz to 6.11 THz. The 3.7 THz bandwidth represents 87% of the central frequency. The proposed UBMA comprises three layers: a star-shaped metal patch on top, a dielectric substrate in the middle, and a metallic ground plane below. Simulations using CST Microwave Studio software reveal that the design achieves high absorption at five distinct frequencies: 2.47, 3.45, 4.89, 6.01, and 6.87 THz, with absorption rates of 99% for the first four peaks and 90% for the fifth peak. The study of electric field and surface current distribution provides insights into the absorption mechanism. While the UBMA exhibits polarization-independent performance, its angular response shows some sensitivity to the incident angle, especially beyond 30° Despite this, the absorber maintains over 70% absorptivity up to a 45° incidence angle for both TE and TM polarizations within specific frequency ranges. The simple structure combined with high absorption efficiency makes the UBMA suitable for THz imaging, detection, and stealth applications, although its angular sensitivity must be considered for certain applications.

Low-profile, low sidelobe array antenna with ultrawide beam coverage for UAV communication

This paper presents a design method to implement an antenna array characterized by ultra-wide beam coverage, low profile, and low Sidelobe Level (SLL) for the application of Unmanned Aerial Vehicle (UAV) air-to-ground communication. The array consists of ten broadside-radiating, ultrawide-beamwidth elements that are cascaded by a central-symmetry series-fed network with tapered currents following Dolph-Chebyshev distribution to provide low SLL. First, an innovative design of end-fire Huygens source antenna that is compatible with metal ground is presented. A low-profile, half-mode Microstrip Patch Antenna (MPA) is utilized to serve as the magnetic dipole and a monopole is utilized to serves as the electric dipole, constructing the compact, end-fire, grounded Huygens source antenna. Then, two opposite-oriented end-fire Huygens source antennas are seamlessly integrated into a single antenna element in the form of monopole-loaded MPA to accomplish the ultrawide, broadside-radiating beam. Particular consideration has been applied into the design of series-fed network as well as antenna element to compensate the adverse coupling effects between elements on the radiation performance. Experiment indicates an ultrawide Half-Power Beamwidth (HPBW) of 161° and a low SLL of −25 dB with a high gain of 12 dBi under a single-layer configuration. The concurrent ultrawide beamwidth and low SLL make it particularly attractive for applications of UAV air-to-ground communication.

A novel filtering patch antenna with high selectivity and wide out‐of‐band suppression

AbstractIn this study, a novel filtering patch antenna with high selectivity and wide out‐of‐band suppression is presented. The antenna consists of a square patch, a metal ground and a feeding line, and four radiation nulls are introduced out of the passband. By designing the stepped feeding line with metal vias, two radiation nulls are introduced out of the passband. A U‐shaped slot is etched on the ground, and a third radiation null is produced. A lowpass filter, integrated into the feeding line, results in the fourth radiation null and the harmonic suppression response. By introducing these structures, the antenna achieves satisfactory frequency selectivity and bilateral wide harmonic suppressions. The proposed design is verified by the simulation and measurement results. Measured impedance bandwidth is 15% (3.33–3.87 GHz), which can perfectly cover the 5G‐N78 band, and measured peak gain can reach 9.0 dBi. The measured edge roll‐off rates in the lower and upper sidebands are 232 and 139 dB/GHz, respectively.

Production of green diesel from waste cooking oil via catalytic deoxygenation reaction using metal doped eggshell catalyst

Abstract Green diesel production via catalytic deoxygenation of waste cooking oil (WCO) over metal doped eggshell catalyst was investigated in this work. The catalyst was prepared through liquid-liquid precipitation of 5 transition metal solutions and ground eggshell (ES) as the catalyst support. The prepared catalyst, Fe-ES, Cu-ES, Co-ES, Zn-ES, and Ni-ES were characterized using BET surface area and Scanning Electron Microscopy (SEM) analysis. BET surface area data and SEM images of the catalyst shows a promising catalyst physical properties that tailor to the deoxygenation reaction. Gas Chromatography Mass Spectrometry (GCMS) was used to determine the hydrocarbon composition of the oil yield product from the reaction. The reaction also produces gas, soap and liquid acid phase while the remaining unreacted WCO becomes coke. The percentage of all products and coke were calculated using mass balance. Deoxygenation of WCO with Ni-ES catalyst produced highest oil yield at 61.6% with the hydrocarbon content of 56.11%. Ni-ES also produced 22.9% coke; the least percentage compared to other catalyst. The findings proved that Ni-ES catalyst exhibited the highest conversion of WCO into gas and liquid product with a greater yield of oil and minimal coke formation. These findings demonstrate the feasibility and practicality of using eggshell catalysts as substitutes for commercial catalysts in green diesel production.

Polarization-multiplexing graphene-based coding metasurface for flexible terahertz wavefront control

In terahertz wireless communication systems, flexible wavefront control devices based on various structure metasurfaces have attracted enormous attention for next-generation communication. In general, tunable terahertz metasurfaces integrated with active materials or MEMS technologies are used for dynamic wavefront control. However, most existing metasurfaces suffer from various limitations, including intrinsic properties of active materials, low reliability of MEMS technologies, and single polarization mode of incident waves, which hinders their development and application. To address these challenges, herein, we design two types of reflective graphene-based coding metasurfaces for active wavefront control. The metasurface coding meta-atom is composed of a graphene split-ring resonator, a dielectric layer, and a metal ground plane. By simply rotating the coding meta-atom, independent 2π phase coverage for circularly polarized (CP) or linearly polarized (LP) illumination can be achieved, enabling polarization multiplexing. Thus, a metasurface (MS-1) is constructed based on the vortex phase profile to generate different wavefronts. Moreover, these wavefronts can be actively switched between a vortex beam, a multi-beam, and a specular reflection beam by altering the polarization mode of the incident waves and the Fermi level of the graphene coding regions Additionally, another metasurface (MS-2) is developed according to the parabolic phase profile to create a tunable metalens that allows active control over focal intensity and depth by adjusting the Fermi level of graphene. Such wavefront-controlled metasurfaces have high capacity and integration, making them very promising for potential applications in terahertz communication and imaging systems.

Reflective Surface for Linear-to-Linear and Linear-to-Circular Polarization Conversion at Multiple Frequencies

In this paper, a thin multiband reflective polarization converter surface is proposed that can reflect a circularly polarized (CP) wave in the following frequency bands: 7.8-8.10 GHz, 8.32-10.04 GHz, 10.80-13.75 GHz, 14.19-14.53 GHz, 16.22-16.52 GHz, and 16.77-17.18 GHz. It can also convert a linearly polarized (LP) incident electromagnetic wave into its orthogonal LP reflection wave in these bands: 8.14-8.25 GHz, 10.23-10.60 GHz, 13.90-14.08 GHz, and 16.59-16.71 GHz. With slotted semicircles supported by a metallic ground plane, the suggested unit cell of the periodic structure has significant stability in all frequency ranges, even at oblique incidence within a 75° angle limit. Furthermore, the suggested polarizer has an easy-to-manufacture construction that only needs one substrate layer and does not include any via holes. A sample prototype consisting of 30×30 unit cells was fabricated and tested, validating our design and simulations.

Pressure-induced semiconductor to metal transition and its impact on the electronic, optical, and thermodynamic properties of the new Kitaev spin liquid candidate CoI2

We investigate the recently identified Kitaev candidate, the unconventional two-dimensional (2D) crystalline material van der Waals CoI2. Our approach involves employing ab-initio calculations to study the effects of applied pressure on its physical properties. CoI2 was found to be a semiconductor with a band gap energy of 2.1 eV. By applying pressure up to 13 GPa, a transition from a semiconductor to a metallic state takes place. This transition was explained by the displacement of the initially filled 5p-iodide band, overlapping with partially filled Co-3d states, leading to the formation of a hybridized conduction band and the emergence of a metallic ground state. Furthermore, by subjecting the CoI2 to pressure, a significant increase of the optical conductivity from 9900 to 11600 (Ω cm)−1, and the refractive index increases from 2.75 to 3.5. Our thermodynamic calculations reveal a captivating tale of CoI2; detecting a peak at 55 K in the temperature-normalized heat capacity which suggests the presence of entropy variation in the material, indicating a shift in the spin configuration within CoI2. In addition, a low thermal conductivity (ranging from 5 to 0.1 W m−1 K−1) underscores the strong interactions among quantum spins.

Triple band terahertz absorption based fractal ring shaped ultrathin mustard oil adulteration sensor

A tri-band terahertz (THz) absorber for sensing the adulteration percentage in mustard oil is proposed in this paper. It consists of a gold based metallic resonating geometry and metallic ground plane on the top and bottom layers of the dielectric material respectively. It has three absorption peaks with peak absorptivity of 99.74%, 99.96% & 99.94% and Full Width at Half Maxima (FWHM) of 0.57, 0.862 & 1.112 THz at 4.6296, 8.295 & 12.6309 THz respectively. The proposed absorber’s unit cell volume has an overall volume of 10 μm×10μm×1.61μm (0.15432λL×0.15432λL×0.024846λL where λL is wavelength at lowest operating frequency i.e. 4.6296 THz). It has polarization insensitive absorption performance under normal incidence and incident angle (θ∘) stability up to 50° for A≥90%. The proposed structure is simulated through by using CST & HFSS. The results are validated by developing an equivalent circuit model (ECM). The results of CST, HFSS and ECM are found to be in good agreement. A sensitivity varying from ∼0.23 THz/RIU to ∼1.62 THz/RIU is achieved for Refractive Index (RI) sensing case, whereas a high sensitivity in the range of ∼0.4 THz/RIU to ∼2 THz/RIU is achieved for mustard oil adulteration sensing case by mounting the absorber’s top surface with a polyimide based container filled with an analyte (either refractive index material or mustard oil). During the validation, a maximum ∼0.16% error in mustard oil adulteration estimation is achieved. The proposed sensor has advantages of simple & ultra compact dimensions, high sensitivity and minimal error in impurity concentration estimation with respect to other absorber-based sensors.

MCML-BF: A Metal-Column Embedded Microstrip Line Transmission Structure with Bias Feeders for Beam-Scanning Leakage Antenna Design.

This article proposes a novel fixed-frequency beam scanning leakage antenna based on a liquid crystal metamaterial (LCM) and adopting a metal column embedded microstrip line (MCML) transmission structure. Based on the microstrip line (ML) transmission structure, it was observed that by adding two rows of metal columns in the dielectric substrate, electromagnetic waves can be more effectively transmitted to reduce dissipation, and attenuation loss can be lowered to improve energy radiation efficiency. This antenna couples TEM mode electromagnetic waves into free space by periodically arranging 72 complementary split ring resonators (CSRRs). The LC layer is encapsulated in the transmission medium between the ML and the metal grounding plate. The simulation results show that the antenna can achieve a 106° continuous beam turning from reverse -52° to forward 54° at a frequency of 38 GHz with the holographic principle. In practical applications, beam scanning is achieved by applying a DC bias voltage to the LC layer to adjust the LC dielectric constant. We designed a sector-blocking bias feeder structure to minimize the impact of RF signals on the DC source and avoid the effect of DC bias on antenna radiation. Further comparative experiments revealed that the bias feeder can significantly diminish the influence between the two sources, thereby reducing the impact of bias voltage introduced by LC layer feeding on antenna performance. Compared with existing approaches, the antenna array simultaneously combines the advantages of high frequency band, high gain, wide beam scanning range, and low loss.

A compact wideband antenna with high gain based on spoof surface plasmon polaritons

In this paper, a novel wideband antenna with a simple structure and low profile based on spoof surface plasmon polaritons (SSPPs) is proposed. The structure consists of periodically modulated corrugated metal strips as transmission lines, a CPW feed, and a ground metal plate as an antenna reflector. The SSPP transmission line is used to convert quasi-TEM to SSPP mode and achieve optimal impedance matching. The prototype of the end-fire antenna has been designed and fabricated. The simulation results show that this antenna can achieve a gain of 10.19 dB, a bandwidth of 146%, and an efficiency of 90% in a wide operating band from 7 to 45 GHz. The proposed design illustrates great potential that includes high efficiency, good directivity, high gain, wide bandwidth, and easy manufacturing.

Prediction of a new 2D Janus monolayer MX2Si2Y2 (M = Mo, W and V; X/Y = N, P; X ≠ Y) from density functional theory

We devised the Janus monolayer MX2A2Y2 (M = Mo, W, V, Nb, Ta, Ti, Zr, Hf and Cr; X/Y = N, P and As; A = Si and Ge) and systematically investigated the structural parameters, phonon vibrations, thermal stability, the electronic and mechanical properties. Among the 26 systems, there are six stable Janus monolayers at room temperature: MoN2Si2P2, WN2Si2P2, VN2Si2P2, MoP2Si2N2, WP2Si2N2, CrN2Si2P2. Intriguingly, the MoP2Si2N2 and WP2Si2N2 show non-magnetic semiconductor properties. The MoN2Si2P2 and WN2Si2P2 demonstrate non-magnetic metallic ground states. The VN2Si2P2 and CrN2Si2P2 are magnetic metal with magnetic moments of 1.24 μB and 0.53 μB. Furthermore, the elastic constants of the MSi2N4 and five Janus monolayer MX2Si2Y2 (M = Mo, W and V; X/Y = N, P) meet the stability criteria, indicating they are mechanically stable. The in-plane stiffness of the MX2Si2Y2 increases with the increase of the number of metal atoms and are greatly reduced, compared with the corresponding MSi2N4. In addition, according to Poisson's ratio, the MN2Si2P2 with metallic characteristics are ductile, whereas the MP2Si2N2 with semiconductor characteristic are brittle. In short, the Janus monolayer MX2Si2Y2 enriches the family members of 2D materials. The rich electronic and mechanical properties make the MX2Si2Y2 have high application prospects for future novel mechanical electronic device applications.