Data from: Current-induced switching of a van der Waals ferromagnet at room temperature
Data files
Feb 12, 2024 version files 3.44 MB
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Figure1.xlsx
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Figure2.xlsx
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Figure3.xlsx
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Figure4.xlsx
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README.md
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SuppFig1.xlsx
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SuppFig2.xlsx
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SuppFig3.xlsx
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Abstract
The recent discovery of emergent magnetism in van der Waals magnetic materials (vdWMM) has broadened the material space for developing spintronic devices for energy-efficient computation. While there has been appreciable progress in vdWMM discovery, a solution for non-volatile, deterministic switching of vdWMMs at room temperature has been missing, limiting the prospects of their adoption into commercial spintronic devices. Here, we report the first demonstration of current-controlled non-volatile, deterministic magnetization switching in a vdW magnetic material at room temperature. We have achieved spin-orbit torque (SOT) switching of the PMA vdW ferromagnet Fe3GaTe2 using a Pt spin-Hall layer up to 320 K, with a threshold switching current density as low as JSW = 1.69
× 106 A cm-2 at room temperature. We have also quantitatively estimated the anti-damping-like SOT efficiency of our Fe3GaTe2/Pt bilayer system to be
ξDL = 0.093, using the second harmonic Hall voltage measurement technique. These results mark a crucial step in making vdW magnetic materials a viable choice for the development of scalable, energy-efficient spintronic devices.
README: Current-induced switching of a van der Waals ferromagnet at room temperature
https://doi.org/10.5061/dryad.1rn8pk11k
The source datafiles are created according to the figures in the manuscript. Each figure (main text or supplemenatary) has it's own .xlsx file. Data corresponding to sub-figures or insets is added to separate spreadsheet pages within the file for that figure. Below we provide detailed description of the data (abbreviations, data arrangement) for all the main text figures. Similar conventions as the main text figures have been followed for the supplementary figures.
Fig.1
(b) X-ray diffration - 2theta vs I (intensity)
(c) Energy dispersive spectroscopy - Energy (E) vs intensity (I)
(d) Hysteresis curves - field vs M (magnetization) at different temperatures (3, 100, 200, 300, 320, 330, ..., 380, 400K). Two columns (field, M) are provided for each temperature.
(e) Anomalous Hall resistance - field (B) vs Hall resistivity (rhoxy) at different temperatures (1.8, 50, 100, ..., 300, 330, 340, ... 370, 400K). Two columns (B, rhoxy) are provided for each temperature.
(e-inset) Temperature, Hall angle (theta_XY)
(f) Field cooling (FC) and zero field cooling (ZFC) data - temperature (T), magnetization (M)
(g) Heat capacity measurement - 3 columns for temperature (T), heat capacity (HC), standard deviation of heat capacity (HC_std), each for measurements under zero magnetic field and 1T magnetic field.
(g-inset) Heat capacity measurement at zero field.
(h) Resistivity measurement - temperature (T), resistivity (rhoxx)
(h-inset) Gradient of resistivity with temperature - temperature (T), gradient (drhoxx/dT)
Fig. 2
(a) Anomalous Hall effect measurement at different temperatures (300, 200, 100, 10K). For each temperature, there are two columns - H (field) and Rxy (Hall resistance)
(b) Anomalous Hall resistance as a function of temperature - Data provided for cooling under +3T and -3T. Plotted data is the difference between the two resistances.
(c) Anomalous Hall resistance for field applied at out-of-plane (0 degree) and in-plane (90 degree). For each angle, there are four columns - backward field, resistance, forward field, resistance.
(d) Magneto-optical Kerr effect (MOKE) measurements - Field (H) and MOKE signal (measured as voltage, V).
(d-inset) Atomic force microscopy (AFM) line profile - x-coordinate (x) and height
(e-inset) Atomic force microscopy (AFM) line profile - x-coordinate (x) and height
(g) Switching data, for four consecutive cycles. Each cycle has two columns - current (I) and Hall resistance (Rxy)
Fig. 3
(b) Time series of Hall resistance measurement - time (t) and resistance (R)
(c) Switching data, for different in-plane magnetic field magnitudes (100, 500, 1000, 1500, 2000, 3000, 4000, 5000 Oe). For each field, there are two columns - current (I) and resistance (R).
(d) Switching data, for different temperatures (300, 310, 320, 330 K). For each temperature, there are two columns - current (I) and resistance (R).
(e) Switched resistance (RxyAHE) for different in-plane fields (H). The data points are derived from the curves in figure 3(c).
(f) Switched resistance (RxyAHE) for different temperatures (T). The data points are derived from the curves in figure 3(d).
Fig. 4
(b) Second harmonic Hall voltage (Vxy2w) variation with angle (phi) of applied magnetic field, for 1 mA AC current. Data is provided for different magnetic field amplitudes (30, 32.5, 35, ..., 55, 60, 65, ... 90 kOe). For each field magnitude, there are four columns - forward angle, voltage, backward angle, voltage.
(c) Second harmonic Hall voltage (Vxy2w) variation with angle (phi) of applied magnetic field, for 1.5 mA AC current. Data is provided for different magnetic field amplitudes (30, 32.5, 35, ..., 55, 60, 65, ... 90 kOe). For each field magnitude, there are four columns - forward angle, voltage, backward angle, voltage.
(d) Amplitude of cos(phi) component (refer to Eq. 2 in main text) of second harmonic voltage, Vxy2w at different magnetic fields, H, at 1 mA and 1.5 mA current levels. These are extracted from the plots in 4(b) and 4(c).
(e) Second harmonic voltage corresponding to damping-like torque (refer to Eq. 3 in main text) of second harmonic voltage, Vxy2w at different magnetic fields, H, at 1 mA and 1.5 mA current levels. These are extracted from the plots in 4(b) and 4(c).
(e-inset) Magnitude of damping-like field (Hdl) for two current levels (I). Lower and upper confidence interval (CI, 5%) are also provided.
SuppFig. 1
Resistivity of platinum (rho_xx) vs temperature (T)
SuppFig. 2
(a-AFM) Atomic force microscopy (AFM) line profile - x-coordinate and height
(b) Anomalous Hall effect - Field and resistance (Rxy)
(c) Current induced switching at positive field (H = 0.1kOe) - Current and resistance (Rxy)
(d) Current induced switching at negative field (H = 0.1kOe) - Current and resistance (Rxy)
SuppFig. 3
(a) Switching data, for different temperatures. Current and resistance (Rxy) columns provided for 270K, 280K and 290K. For 300K-330K, the current column is the same, and respective resistance (Rxy) columns are provided.
(b) Switched resistance (RxyAHE) and switching current (Isw) for different temperatures (T). The data points are derived from the curves in figure S3(a).
(c) Switching data, for different in-plane magnetic field magnitudes (0.1, 0.5, 1, 2, 3, ..., 10kOe). Current column is common for all cases, and resistance (Rxy) recorded for each case is provided.
(d) Switched resistance (RxyAHE) for different in-plane fields (H). The data points are derived from the curves in figure S3(c).
SuppFig. 4
(a) Current pulsing for different magnetic fields (0, 100, 500, 1000 Oe) applied out of plane. Current column is common for all cases, and resistance (Rxy) recorded for each case is provided.
(b) Current pulsing for different magnetic fields (0, 100, 500, 1000 Oe) applied in-plane but perpendicular to current. Current column is common for all cases, and resistance (Rxy) recorded for each case is provided.
SuppFig. 5
(a) Second harmonic Hall voltage (Vxy2w) variation with angle (phi) of applied magnetic field, for 1 mA AC current. Data is provided for different magnetic field amplitudes (45, 47.5, ..., 65, 70, ..., 90 kOe). For each field magnitude, there are four columns - forward angle, voltage, backward angle, voltage.
(b) Second harmonic Hall voltage (Vxy2w) variation with angle (phi) of applied magnetic field, for 1.5 mA AC current. Data is provided for different magnetic field amplitudes (45, 47.5, ..., 65, 70, ..., 90 kOe). For each field magnitude, there are four columns - forward angle, voltage, backward angle, voltage.\
(c) Second harmonic Hall voltage (Vxy2w) variation with angle (phi) of applied magnetic field, for 2 mA AC current. Data is provided for different magnetic field amplitudes (45, 47.5, ..., 65, 70, ..., 90 kOe). For each field magnitude, there are four columns - forward angle, voltage, backward angle, voltage.\
(d) Amplitude of cos(phi) component (refer to Eq. 2 in main text) of second harmonic voltage, Vxy2w at different magnetic fields, H, at 1 mA, 1.5mA and 2 mA current levels. These are extracted from the plots in S5(a), S5(b) and S5(c).\
(e) Second harmonic voltage corresponding to damping-like torque (refer to Eq. 3 in main text) of second harmonic voltage, Vxy2w at different magnetic fields, H, at 1 mA, 1.5mA and 2 mA current levels. These are extracted from the plots in S5(a), S5(b) and S5(c).\
(e-inset) Magnitude of damping-like field (Hdl) for two current levels (I). Lower and upper confidence interval (CI, 5%) are also provided.
SuppFig. 6
(c) Atomic force microscopy (AFM) line profile - x-coordinate and height
(d) Switching data - current and resistance
(e) Time series of Hall resistance measurement - time and resistance
(h) Atomic force microscopy (AFM) line profile - x-coordinate and height
(i) Switching data - current and resistance
(j) Time series of Hall resistance measurement - time and resistance
Methods
Bulk Crystal Characterisation
Powder X-ray diffraction (PXRD) data were measured on bulk samples using an X’Pert Pro diffractometer (PANalytical) in Bragg-Brentano geometry operating with a curved Ge(111) monochromator and Cu Kα1 radiation with a wavelength of 0.154 nm. Scanning electron microscope (SEM) images on both bulk crystals and exfoliated flakes on SiO2 substrates are measured using a Zeiss Merlin high-resolution SEM system with images acquired at an acceleration voltage of 20 kV, a current of 1000 pA, and a working distance of 8.5 mm. SEM-energy dispersive X-ray spectroscopy (EDS) elemental maps were taken using the EDAX APEX software.
Electrical transport measurements were performed on the bulk crystals in a Physical Property Measurement System (PPMS Dynacool, Quantum Design) in a five-probe geometry with contacts made of silver epoxy H20E and platinum wires. Direct current magnetization of the sample was acquired using the Vibrating Sample Magnetometer (VSM) option on crystals placed in the proper orientation using Kapton tape on a quartz holder (OOP) or using a Brass holder (IP). Temperature-dependent field-cooled and zero-field-cooled magnetization measurements were performed with an applied magnetic field of 1000 Oe. Specific heat capacity was measured on a 4.4 mg crystal using the Heat Capacity (HC) option with Apiezon H vacuum grease applied on the platform.
Transport measurements in devices
All transport measurements were performed in a 9 T PPMS DynaCool system. Anomalous Hall effect measurements on the FGaT-only devices were performed using the Electrical Transport Option of the PPMS Dynacool, with a drive current of 100 A. Current-induced switching experiments were performed by interfacing a Keithley 6221 current source and 2182A nanovoltmeter with the PPMS Dynacool. Current input sequence consisted of a 1 ms write-pulse followed by 999 ms of read pulses (
200
A). For second harmonic Hall measurements, AC current was supplied by the Keithley 6221, at a frequency 1711.97 Hz. Two lock-in amplifiers, Stanford Research Systems (SRS) SR860 were used to simultaneously measure
and
transverse voltage components.