Research On Nonlinearity And Sensing Application Of CrPS₄ Mechanical Resonator

In the past decades,from graphene to transition metal dichalcogenides and further to layered ternary chalcogenides,atomic-scale two-dimensional materials have triggered extensive studies because of their atomic thickness and excellent electrical,optical and mechanical properties,which have gradually become ideal materials for the research of innovative two-dimensional（2D）nanoelectromechanical systems（NEMS）and the exploration of nonlinear dynamics and high-precision devices.As a novel material,Cr PS4has also gradually attracted attention due to its excellent mechanical and magnetic properties.Here,the study firstly fabricate the Cr PS₄ mechanical resonators based on the micro and nanotechnology,and explore it by the optical interferometry method.Working in the limits of atomic thin films,the resonance frequency of the Cr PS₄is mainly determined by the pre-tension in the membrane.Here,the study demonstrates thin semiconductor NEMS resonators with electrical tunability under electrostatic excitation and characterize their dynamic behavior.The study showed the very high working frequency（up to～88 MHz）,excellent quality factor and frequency electrical tunability,which is essential for applications such as tunable RF signal transduction,generation and communication.Behavior of magnetic materials as Cr PS₄ is of interest,since their mechanical motions are strongly coupled to both the magnetic phase and the magnetization of that phase.This characteristic will induce an extraordinary trend of Q of temperature dependence,in particular at the Néel temperature,which presents a new paradigm for mechanical detection of Cr PS₄ magnetism.From the completely undriven Brownian motion thermomechanical noise floor to the nonlinear responses with increasing driving power under different temperatures.The study use suspended double clamped antiferromagnetic Cr PS₄ membranes to present and analysis the various mode characteristics and nonlinear responses of membranes.Increased input driving force induces large vibration-induced strain in the device,resulting in observed effects from nonlinearities,which in turn induce detuning in the resonant frequency and Q factor.Unlike previous studies on Dynamic Range（DR）in the room temperature domain,where the Q factor of Brownian motion are approximately calibrated to the low driving power,thus yielding imprecise DR even wrong DR,here,the study achieve measurement down to the device intrinsic noise floors that the minimum temperature is down to 5K,thus capable of resolving the precise DR（up to 88～110 d B）in the actual displacement domain of membrane motion.Here,the study approach a remarkable displacement resolution of 16 fm/Hz^1/2 and achieved a ultra-high sensitivity mass sensing up to～1 yg.Together,this precise measurement and calibration of atomic layer crystals for this 2D NEMS resonator significantly facilitates the achievement of broad and stable DRs devices,enables ultralow-power and ultrasensitive resonant transduction for sensing and information processing applications.