Sub-Ångstrom electric field measurements on a universal detector in a scanning transmission electron microscope
Tóm tắt
Scanning transmission electron microscopy (STEM) excels in accessing atomic-scale structure and chemistry. Enhancing our ability to directly image the functionalities of local features in materials has become one of the most important topics in the future development of STEM. Recently, differential phase contrast (DPC) imaging has been utilized to map the internal electric and magnetic fields in materials from nanoscale features such as p–n junctions, skyrmions, and even from individual atoms. Here, we use an ultra-low noise SCMOS detector in as the diffraction plane camera to collect four-dimensional (4D) datasets. The high angular resolution, efficient high-SNR acquisition, and modifiability of the camera allow it to function as a universal detector, where STEM imaging configurations, such as DPC, bright field, annular bright field, and annular dark field can all be reconstructed from a single 4D dataset. By examining a distorted perovskite, DyScO3, which possesses projected lattice spacings as small as 0.83 Å, we demonstrate DPC spatial resolution almost reaching the information limit of a 100 keV electron beam. In addition, the perovskite has ordered O-coordinations with alternating octahedral tilts, which can be quantitatively measured with single degree accuracy by taking advantage of DPC’s sensitivity to light atoms. The results, acquired on a standard Ronchigram camera as opposed to a specialized DPC detector, open up new opportunities to understand and design functional materials and devices that involve lattice and charge coupling at nano- and atomic-scales.
Tài liệu tham khảo
Dekker, N.H., de Lang, H.: Differential phase contrast in a STEM. Optik 41, 452–456 (1974)
Chapman, J.N., Batson, P.E., Waddell, E.M., Ferrier, R.P.: The direct determination of magnetic domain wall profiles by differential phase contrast electron microscopy. Ultramicroscopy 3, 203–214 (1978). https://doi.org/10.1016/S0304-3991(78)80027-8
Toriumi, A., Herrmann, J.M., Kawata, S.: Nondestructive readout of a three-dimensional photochromic optical memory with a near-infrared differential phase-contrast microscope. Opt. Lett. 22, 555–557 (1997). https://doi.org/10.1364/OL.22.000555
Pfeiffer, F., Weitkamp, T., Bunk, O., David, C.: Phase retrieval and differential phase-contrast imaging with low-brilliance X-ray sources. Nat. Phys. 2, 258–261 (2006). https://doi.org/10.1038/nphys265
Stampanoni, M., Wang, Z., Thüring, T., David, C., Roessl, E., Trippel, M., Kubik-Huch, R.A., Singer, G., Hohl, M.K., Hauser, N.: The first analysis and clinical evaluation of native breast tissue using differential phase-contrast mammography. Invest. Radiol. 46, 801 (2011). https://doi.org/10.1097/RLI.0b013e31822a585f
Shibata, N., Findlay, S.D., Sasaki, H., Matsumoto, T., Sawada, H., Kohno, Y., Otomo, S., Minato, R., Ikuhara, Y.: Imaging of built-in electric field at a p–n junction by scanning transmission electron microscopy. Sci. Rep. 5, 10040 (2015). https://doi.org/10.1038/srep10040
Lohr, M., Schregle, R., Jetter, M., Wächter, C., Müller-Caspary, K., Mehrtens, T., Rosenauer, A., Pietzonka, I., Strassburg, M., Zweck, J.: Quantitative measurements of internal electric fields with differential phase contrast microscopy on InGaN/GaN quantum well structures. Phys. Status Solidi B 253, 140–144 (2015). https://doi.org/10.1002/pssb.201552288
Lee, S.J., Lee, H.J., Song, K., Choi, S.Y., Park, H.S.: In-situ observation of domain wall motion in electroplated Ni80–Fe20 thin film by lorentz TEM and DPC imaging. J. Magn. 22, 563–569 (2017)
Almeida, T.P., Temple, R., Massey, J., Fallon, K., McGrouther, D., Moore, T., Marrows, C.H., McVitie, S.: Quantitative TEM imaging of the magnetostructural and phase transitions in FeRh thin film systems. Sci. Rep. 7, 17835 (2017). https://doi.org/10.1038/s41598-017-18194-0
Chen, C., Li, H., Seki, T., Yin, D., Sanchez-Santolino, G., Inoue, K., Shibata, N., Ikuhara, Y.: Direct determination of atomic structure and magnetic coupling of magnetite twin boundaries. ACS Nano 12, 2662–2668 (2018). https://doi.org/10.1021/acsnano.7b08802
Campanini, M., Erni, R., Yang, C., Ramesh, R., Rossell, M.D.: Periodic giant polarization gradients in doped BiFeO3 thin films. Nano Lett. 18, 717–724 (2018). https://doi.org/10.1021/acs.nanolett.7b03817
Matsumoto, T., So, Y.-G., Kohno, Y., Sawada, H., Ikuhara, Y., Shibata, N.: Direct observation of Σ7 domain boundary core structure in magnetic skyrmion lattice. Sci. Adv. 2, e1501280 (2016). https://doi.org/10.1126/sciadv.1501280
Shibata, N., Findlay, S.D., Kohno, Y., Sawada, H., Kondo, Y., Ikuhara, Y.: Differential phase-contrast microscopy at atomic resolution. Nat. Phys. 8, 611–615 (2012). https://doi.org/10.1038/nphys2337
Shibata, N., Seki, T., Sánchez-Santolino, G., Findlay, S.D., Kohno, Y., Matsumoto, T., Ishikawa, R., Ikuhara, Y.: Electric field imaging of single atoms. Nat. Commun. 8, 15631 (2017). https://doi.org/10.1038/ncomms15631
Shibata, N., Findlay, S.D., Matsumoto, T., Kohno, Y., Seki, T., Sánchez-Santolino, G., Ikuhara, Y.: Direct visualization of local electromagnetic field structures by scanning transmission electron microscopy. Acc. Chem. Res. 50, 1502–1512 (2017). https://doi.org/10.1021/acs.accounts.7b00123
Lazić, I., Bosch, E.G.T., Lazar, S.: Phase contrast STEM for thin samples: integrated differential phase contrast. Ultramicroscopy 160, 265–280 (2016). https://doi.org/10.1016/j.ultramic.2015.10.011
Yücelen, E., Lazić, I., Bosch, E.G.T.: Phase contrast scanning transmission electron microscopy imaging of light and heavy atoms at the limit of contrast and resolution. Sci. Rep. 8, 2676 (2018). https://doi.org/10.1038/s41598-018-20377-2
Pennycook, T., Lupini, A.R., Yang, H., Murfitt, M.F., Jones, L., Nellist, P.D.: Efficient phase contrast imaging in STEM using a pixelated detector. Part I: experimental demonstration at atomic resolution. Ultramicroscopy 151, 160–167 (2015). https://doi.org/10.1016/j.ultramic.2014.09.013
Yang, H., Pennycook, T.J., Nellist, P.D.: Efficient phase contrast imaging in STEM using a pixelated detector. Part II: optimisation of imaging conditions. Ultramicroscopy 151, 232–239 (2015). https://doi.org/10.1016/j.ultramic.2014.10.013
Cao, M.C., Han, Y., Chen, Z., Jiang, Y., Nguyen, K.X., Turgut, E., Fuchs, G.D., Muller, D.A.: Theory and practice of electron diffraction from single atoms and extended objects using an EMPAD. Microscopy. 67, 150–161 (2018). https://doi.org/10.1093/jmicro/dfx123
Lupini, A.R., Chi, M., Jesse, S.: Rapid aberration measurement with pixelated detectors. J. Microsc. 263, 43–50 (2016). https://doi.org/10.1111/jmi.12372
Krajnak, M., McGrouther, D., Maneuski, D., Shea, V.O., McVitie, S.: Pixelated detectors and improved efficiency for magnetic imaging in STEM differential phase contrast. Ultramicroscopy 165, 42–50 (2016). https://doi.org/10.1016/j.ultramic.2016.03.006
Müller, K., Krause, F.F., Béché, A., Schowalter, M., Galioit, V., Löffler, S., Verbeeck, J., Zweck, J., Schattschneider, P., Rosenauer, A.: Atomic electric fields revealed by a quantum mechanical approach to electron picodiffraction. Nat. Commun. 5, 5653 (2014). https://doi.org/10.1038/ncomms6653
Yang, H., Rutte, R.N., Jones, L., Simson, M., Sagawa, R., Ryll, H., Huth, M., Pennycook, T.J., Green, M.L.H., Soltau, H., Kondo, Y., Davis, B.G., Nellist, P.D.: Simultaneous atomic-resolution electron ptychography and Z-contrast imaging of light and heavy elements in complex nanostructures. Nat. Commun. 7, 12532 (2016). https://doi.org/10.1038/ncomms12532
Ophus, C., Ciston, J., Pierce, J., Harvey, T.R., Chess, J., McMorran, B.J., Czarnik, C., Rose, H.H., Ercius, P.: Efficient linear phase contrast in scanning transmission electron microscopy with matched illumination and detector interferometry. Nat. Commun. 7, 10719 (2016). https://doi.org/10.1038/ncomms10719
Jiang, Y., Chen, Z., Han, Y., Deb, P., Gao, H., Xie, S., Purohit, P., Tate, M.W., Park, J., Gruner, S.M., Elser, V., Muller, D.A.: Electron ptychography of 2D materials to deep sub-Ångström resolution. Nature 559, 343–349 (2018). https://doi.org/10.1038/s41586-018-0298-5
Lupini, A.R., Chi, M., Kalinin, S.V., Borisevich, A.Y., Idrobo, J.C., Jesse, S.: Ptychographic imaging in an aberration corrected STEM. Microsc. Microanal. 21, 1219–1220 (2015). https://doi.org/10.1017/S1431927615006881
Nellist, P.D., Chisholm, M.F., Dellby, N., Krivanek, O.L., Murfitt, M.F., Szilagyi, Z.S., Lupini, A.R., Borisevich, A., Sides, W.H., Pennycook, S.J.: Direct sub-Angstrom imaging of a crystal lattice. Science 305, 1741 (2004). https://doi.org/10.1126/science.1100965
Ishikawa, R., Okunishi, E., Sawada, H., Kondo, Y., Hosokawa, F., Abe, E.: Direct imaging of hydrogen-atom columns in a crystal by annular bright-field electron microscopy. Nat. Mater. 10, 278–281 (2011). https://doi.org/10.1038/nmat2957
Yang, H., MacLaren, I., Jones, L., Martinez, G.T., Simson, M., Huth, M., Ryll, H., Soltau, H., Sagawa, R., Kondo, Y., Ophus, C., Ercius, P., Jin, L., Kovács, A., Nellist, P.D.: Electron ptychographic phase imaging of light elements in crystalline materials using Wigner distribution deconvolution. Ultramicroscopy 180, 173–179 (2017). https://doi.org/10.1016/j.ultramic.2017.02.006
Rodenburg, J.M., Bates, R.H.T.: The theory of super-resolution electron microscopy via Wigner-distribution deconvolution. Philos. Trans. Phys. Sci. Eng. 339, 521–553 (1992)
Haeni, J.H., Irvin, P., Chang, W., Uecker, R., Reiche, P., Li, Y.L., Choudhury, S., Tian, W., Hawley, M.E., Craigo, B., Tagantsev, A.K., Pan, X.Q., Streiffer, S.K., Chen, L.Q., Kirchoefer, S.W., Levy, J., Schlom, D.G.: Room-temperature ferroelectricity in strained SrTiO3. Nature 430, 758–761 (2004). https://doi.org/10.1038/nature02773
Kadlec, C., Kadlec, F., Němec, H., Kužel, P., Schubert, J., Panaitov, G.: High tunability of the soft mode in strained SrTiO 3/DyScO3 multilayers. J. Phys. Condens. Matter 21, 115902 (2009). https://doi.org/10.1088/0953-8984/21/11/115902
Close, R., Chen, Z., Shibata, N., Findlay, S.D.: Towards quantitative, atomic-resolution reconstruction of the electrostatic potential via differential phase contrast using electrons. Ultramicroscopy 159(Part 1), 124–137 (2015). https://doi.org/10.1016/j.ultramic.2015.09.002
Liferovich, R.P., Mitchell, R.H.: A structural study of ternary lanthanide orthoscandate perovskites. J. Solid State Chem. 177, 2188–2197 (2004). https://doi.org/10.1016/j.jssc.2004.02.025
Krivanek, O.L., Corbin, G.J., Dellby, N., Elston, B.F., Keyse, R.J., Murfitt, M.F., Own, C.S., Szilagyi, Z.S., Woodruff, J.W.: An electron microscope for the aberration-corrected era. Ultramicroscopy 108, 179–195 (2008). https://doi.org/10.1016/j.ultramic.2007.07.010
Spiegelberg, J., Idrobo, J.C., Herklotz, A., Ward, T.Z., Zhou, W., Rusz, J.: Local low rank denoising for enhanced atomic resolution imaging. Ultramicroscopy 187, 34–42 (2018). https://doi.org/10.1016/j.ultramic.2018.01.012
Borisevich, A., Ovchinnikov, O.S., Chang, H.J., Oxley, M.P., Yu, P., Seidel, J., Eliseev, E.A., Morozovska, A.N., Ramesh, R., Pennycook, S.J., Kalinin, S.V.: Mapping octahedral tilts and polarization across a domain wall in BiFeO3 from Z-contrast scanning transmission electron microscopy image atomic column shape analysis. ACS Nano 4, 6071–6079 (2010). https://doi.org/10.1021/nn1011539
Liao, Z., Huijben, M., Zhong, Z., Gauquelin, N., Macke, S., Green, R.J., Van Aert, S., Verbeeck, J., Van Tendeloo, G., Held, K., Sawatzky, G.A., Koster, G., Rijnders, G.: Controlled lateral anisotropy in correlated manganite heterostructures by interface-engineered oxygen octahedral coupling. Nat. Mater. 15, 425–431 (2016). https://doi.org/10.1038/nmat4579
Han, Y., Nguyen, K., Cao, M., Cueva, P., Xie, S., Tate, M.W., Purohit, P., Gruner, S.M., Park, J., Muller, D.A.: Strain mapping of two-dimensional heterostructures with sub-picometer precision. ArXiv180108053. Cond-Mat. Physicsphys. (2018)
Krehl, J., Guzzinati, G., Schultz, J., Potapov, P., Pohl, D., Martin, J., Verbeeck, J., Fery, A., Büchner, B., Lubk, A.: Spectral field mapping in plasmonic nanostructures with nanometer resolution. ArXiv180304399. Cond-Mat. Physicsphys. (2018)