1. ABOUT THE DATASET -------------------- Title: Dataset for 'A Hybrid Magneto-Optic Capacitive Memory with Picosecond Writing Time' Creator(s): M. Rogers[1], A. Habib[1,2], G. Teobaldi[3,4], T. Moorsom[1], J.O. Johansson[5], L. Hedley[5], P.S. Keatley[6], R.J. Hicken[6], M. Valvidares[7], P. Gargiani[7], N. Alosaimi[1], E. Poli[3], M. Ali[1], G. Burnell[1], B.J. Hickey[1] and O. Cespedes[1] Organisation(s): 1. School of Physics and Astronomy, University of Leeds, Leeds, U.K., 2. Science, Engineering & Technology School, Khulna University, Khulna-9208, Bangladesh, 3. Scientific Computing Department, Science & Technology Facilities Council UKRI, Rutherford Appleton Laboratory, Didcot, U.K., 4. School of Chemistry, University of Southampton, Southampton, U.K., 5. EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh, U.K., 6. School of Physics, University of Exeter, Exeter, U.K., 7. ALBA Synchrotron Light Source, E-08290 Barcelona, Spain. Rights-holder(s):Copyright 2023 University of Leeds Publication Year: 2023 Description: This dataset contains the magneto-optic Kerr images and hysteresis loops measured at room temperature, density functional theory computational results, time-resolved transient spectroscopy, Xray absorption spectroscopy and transport measurements for for Co/C60/MnOx samples as reported in the manuscript A Hybrid Magneto-Optic Capacitive Memory with Picosecond Writing Time published in Advanced Functional Materials. Cite as: M. Rogers et al. (2023): Dataset for 'A Hybrid Magneto-Optic Capacitive Memory with Picosecond Writing Time. University of Leeds. https://doi.org/10.5518/1256. Related publication: M. Robers et al., A Hybrid Magneto-Optic Capacitive Memorey with Picosecond Writing Time. Advanced Functional Materials 33, 2212173 (2023) Contact: o.cespedes@leeds.ac.uk 2. TERMS OF USE --------------- Copyright 2023. University of Leeds, Matthew Rogers, Oscar Cespedes. This dataset is licensed under a Creative Commons Attribution 4.0 International Licence: https://creativecommons.org/licenses/by/4.0 3. PROJECT AND FUNDING INFORMATION ---------------------------------- Title: Spintronics at Leeds Dates: 13/10/2014 - 12/04/2020 Funding organisation: Engineering and Physical Sciences Research Council Grant no.: EP/M000923/1 Title: EPSRC-SFI: Emergent Magnetism and Spin Interactions in Metallo-Molecular Interfaces Dates: 28/10/2019 - 27/04/2024 Funding organisation: Engineering and Physical Sciences Research Council Grant no.: EP/S030263/1 (Leeds) and EP/S031081/1 (STFC) Title: EXTREMAG: an Exeter-based Time Resolved Magnetism Facility Dates: 01/01/2018 - 31/01/2024 Funding organisation: Engineering and Physical Sciences Research Council Grant no.: EP/R008809/1 Title: Expanded access to the Exeter time resolved magnetism (EXTREMAG) facility Dates: 01/10/2021 - 30/09/2023 Funding organisation: Engineering and Physical Sciences Research Council Grant no.: EP/V054112/1 4. CONTENTS ----------- File listing All opju files are accessible with OriginLAb 2019 or a newer version of the same software (https://www.originlab.com/) Fig1c_PVMap_1 and _2.opju - raw data for short circuit photocurrent (_1) and open circuit voltage (_2)) in photovoltaic maps in C0/C60/MnOx as reported in figure 1c of the manuscript. Data shows the electrical (current/voltage) measurements across spatial x, y coordinates in the junction. Fig1d_HLoops.opju - hysteresis loops in the same sample structure measured via white light Kerr microscopy as reported in figure 1d of the manuscript. Loops have been corrected for Faraday effect and normalised. File accessible with OriginLab version 2019 or newer. Fig2a_CONTCAR-0_02.txt - optimised (0.02 eV/Ang) geometry of the interface model in VASP POSCAR format as reported in figure 2a of the manuscript. Txt files in figure 2 accessible with notepad or a word processor. Fig2b_DOS_MnO2.txt - spin-channel resolved PDOS for the MnO2 slab (top panel in Fig. 2b of the manuscript. Fig2b_DOS.c60_layer_1, _2 and _3.txt - spin-channel resolved PDOS for C60 (1st/2nd/3rd) layers (middle panel in Fig. 2b of the manuscript). Fig2b_DOS_Co.txt - spin-channel resolved PDOS for the Co slab (bottom panel in Fig. 2b of the manuscript). Fig2c_XLD.opju - Xray linear dichroism data for ground and electrically charged Co/C60/MnOx structures with magnetic fields between -1 to +1 Tesla as per figure 2c in the main manuscript. File includes a schematic of the sample configuration w.r.t. the applied magnetic field. Fig2d_PVOr - Normalised short-circuit photocurrent measured in a device as a function of the relative alignment of the incident light polarization with the magnetisation of the cobalt electrode, reported in figure 2d of the manuscript. Figure 3c_TA_1 _2, _3 and _4.opju - Time-resolved TA spectroscopy for C60 and a magneto-photovoltaic structure in different electrical and magnetic configurations. The data corresponds to results showin in figure 3c of the manuscript. The data shows changes in the optical absorption of the device with pump irradiation at 520 nm as a function of time (after 0.5 '_1', 2 '_2', 10 '_3' and 500 '_4' ps) for wavelengths between ~330 and 520 nm. Figure 3d_TA_1 and 2.opju - Time-resolved TA spectroscopy comparison for a magneto-photovoltaic structure during an applied out of plane (OOP; _1) and in-plane (IP; _2) magnetic field -as reported in figure 3d of the manuscript. Fig4b_Kittel - Results from time resolved scanning Kerr microscopy measurements showing the Kittel parameters of ferromagnetic resonance in Co/C60/MnOx with a two frequency fit and as a function of the relative alignment (phi) between the measurement light polarisation and the electrode magnetisation. Fig4c_TRSKM_1, _2, _3 and _4.opju - Normalised data for time-resolved scanning Kerr microscopy measurements at 10 mT (_1, _3) and 40 mT (_2, _4) and measured at 0 degrees (_2, _4) and 90 degrees (_1, _3) between the light polarisation and the magnetisation. Measurements between 0 and 1.4 (10 mT) or 2.5 ns (40 mT). Data as reported in figure 4c of the manuscript. Fig4d_Damping - Resulting Gilbert damping (as a frequency) for the different sample configurations and geometries. 5. METHODS ---------- Measurements reported here were taken at room temperature and pressure unless otherwise specified. All layers of the device are grown in-situ without breaking vacuum at a base pressure of ~10^-8 mTorr. Electrodes are deposited via DC magnetron sputtering (Co) and plasma oxidation (MnO2) on a transparent insulating substrate. C60 has a long spin coherence time and is highly resilient to the sputtering on top of metals and plasma oxidation. It has a low vapour pressure compatible with UHV growth, and layers are deposited in-situ via thermal evaporation at ~450 °C. The films are polycrystalline, with a grain size of several 10s of nm. Devices had a resistance of ~M at low voltages for a typical 100×100 m2 junction area. The high resistance reduces the photocurrent but improves the information storage effect via the spin polarised trapped electrons. A thermal voltage and current can be measured upon laser excitation, but these are orders of magnitude smaller than the photovoltaic effect. Unlike the current and voltage generated by photo-excited carriers, the polarity of the thermal voltage/current is dependent on whether the light is incident on the oxide or the metal (front or back of sample) and can therefore be trivially excluded. XAS and XMCD spectra(data) were measured in the BOREAS beamline at the ALBA synchrotron in Barcelona, Spain. The X-ray beam is produced by an elliptically polarized undulator and monochromatized by a variable line spacing grating monochromator (400 lines/mm at Carbon edge), with a total flux of the order of 1011 photons/s at the Carbon edge. The beam was collimated by variable focusing bender mirrors down to about 100 x 50 micron approximately, allowing the junction area to be accurately located via triangulation with the electrodes, further detail can be found in the supplementary information. The measurements were carried out at the hybridization energy of the carbon K-edge (~282 eV) in devices after different electrical inputs. Samples were measured in vacuum at room temperature and under magnetic fields up to 1 Tesla. The details of the transient absorption spectrometer are as follows; the 120 fs 800 nm output from a Coherent Legend Elite, operating at 1 kHz, was directed into a non-collinear optical parametric amplifier to produce 550 nm 80 fs pump pulses. The pulse fluence at the sample was 1.8 mJ/cm2. A small portion of the 800 nm output was focussed into a CaF2 plate to generate a white-light continuum, which was further split into a probe and reference beam. Each of these beams were sent to two home-built prism spectrometers equipped with CCD cameras (Entwicklungsbuero Stresing) operating at 1 kHz. Data collected at the University of Edinburgh. Time-resolved polar Kerr measurements in response to a pulsed magnetic field were performed at normal incidence in a scanning microscope were collected at the EXTREMAG facility at Exeter University. Probing laser pulses were generated from a mode-locked fibre laser with a repetition rate of 80 MHz and pulse duration of 140 fs at a wavelength of 1040 nm. Magnetisation dynamics were probed at the second harmonic wavelength of 520 nm attenuated to an average power of not more than 1 mW before the microscope objective lens. Probe pulses were linearly polarised and focused to a microscale spot using either a x10 objective lens or a 40 mm plano-convex lens. The time delay of the probing laser pulses with respect to the pulsed magnetic field excitation was set using an 8 ns optical delay line with sub-ps resolution. The 80 MHz laser sync output was used as a clock input for an impulse generator to generate electrical pulses with ~5 V amplitude, and 70 ps duration that were synchronous with the probe laser pulses. The electrical pulses were passed through a coplanar waveguide with centre conductor width of either 0.5 mm or 1 mm. The associated in-plane pulsed magnetic field above the centre conductor was then used to excite magnetization dynamics in the device that was placed face down upon the waveguide, while the in-plane equilibrium magnetic state of the device was set using either a tri-pole 3D projected field electromagnet, or a stack of permanent magnets mounted on a translation stage. The polar magneto-optical Kerr effect was then used to probe the dynamic state of the out-of-plane component of the magnetization as a function of optical time delay in time-resolved Kerr measurements. The Kerr measurements were probed through a transparent substrate so that the device was in good proximity with the coplanar waveguide and excitation field. Polar Kerr signals corresponding to the change in the out-of-plane component of the dynamic magnetization were detected using a balanced photodiode polarizing bridge detector with a 1 MHz bandwidth. Modulation of the pulsed field excitation at ~30 kHz allowed the modulated change in the polar Kerr rotation to be recovered using a lock-in amplifier with ~10 microdeg resolution.