METHOD FOR DETERMINING LOCAL DEFORMATION IN DIAMOND CRYSTAL USING OPTICALLY DETECTED MAGNETIC RESONANCE NV-DEFECTS Russian patent published in 2023 - IPC C30B29/04 G01N21/64 G01N22/02 G01N24/00 B82B1/00 B82Y35/00 

FIELD: nanotechnology.

SUBSTANCE: used in the manufacture of materials for magnetometry, quantum optics, biomedicine, as well as in information technology based on the quantum properties of spins and single photons. A method for determining local deformation in a diamond crystal using optically detectable magnetic resonance (ODMR) of NV-defects includes exposing the diamond crystal to focused laser radiation, which excites photoluminescence (PL) of the NV-defect in the working volume of the diamond sample, by which the ODMR signal of NV-defects is recorded in the form of a change in the intensity of photoluminescence from frequency. First, the ODMR spectra of NV-defects are recorded as a change in the intensity of photoluminescence from frequency in control diamond samples with different voltages. In each control sample, the splitting caused by local stress near the NV-defect and caused by the deviation of the crystal field from the axial field is determinedΔ, MHz of the ODMR signal of NV-defects between the levels degenerate in the axial crystal field with spin projections +1 and -1, while the zero reference point is the frequency of 2870 MHz for an ideal structure in which there are no internal stresses. Next, determine the local stressσ from the relationσ=28.5*Δ , where 28.5 is a constant, MPa/MHz,Δ is a level splitting with spin projections +1 and -1, MHz. After that, a calibration curve of the dependence of the local stress is builtσ from the valueΔ in control samples. From the ODMR spectra of NV-defects of the crystal under study, the valueΔ is determined in the test sample. Using the previously constructed calibration curve, by valueΔ in the test sample determine the local stressσ of the studied sample, and then - local deformation in the studied diamond crystal from the following ratio:ε =σ /E_diam, whereε is the local deformation, dimensionless quantity,σ is the local stress, MPa, E_diam. is the Young's modulus in diamond, equal to 1.2⋅ 10⁶ MPa. To excite photoluminescence in the working volume of a diamond crystal sample by focused laser radiation, confocal optics are used. An array of diamond nanocrystals can be used as a sample of a diamond crystal and a single NV-defect can be chosen. A sample of a diamond crystal is placed in water or in a liquid transparent in the visible optical range with a refractive index in the visible range lower than in diamond.

EFFECT: simplification of the process for determining local deformation in a diamond crystal.

4 cl, 6 dwg, 2 ex