This readme file was updated on 2023-04-15 by Xiaojia Wang ------------------- GENERAL INFORMATION ------------------- Title of Dataset: Supporting Data for Wide-range continuous tuning of the thermal conductivity of La0.5Sr0.5CoO3-delta films via room-temperature ion-gel gating Author Information: Principal Investigator Contact Information Name: Xiaojia Wang Institution: University of Minnesota Address: Department of Mechanical Engineering, 111 Church ST. SE., Minneapolis, Minnesota 55455 Email: wang4940@umn.edu ORCID: 0000-0001-7612-1739 Associate or Co-investigator Contact Information Name: Chris Leighton Institution: University of Minnesota Address: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN55455, USA Email: leighton@umn.edu ORCID: 0000-0003-2492-0816 Associate or Co-investigator Contact Information Name: Tianli Feng Institution: University of Utah Address: Department of Mechanical Engineering, University of Utah, Salt Lake City, Utah 84112, USA Email: tianli.feng@utah.edu ORCID: 0000-0002-7284-5657 Associate or Co-investigator Contact Information Name: Yingying Zhang Institution: University of Minnesota Address: Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN55455, USA Email: zhan5628@umn.edu ORCID: 0000-0002-3275-5462 Associate or Co-investigator Contact Information Name: William M. Postiglione Institution: University of Minnesota Address: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN55455, USA Email: post0127@umn.edu ORCID: 0000-0002-5301-863X Associate or Co-investigator Contact Information Name: Rui Xie Institution: University of Utah Address: Department of Mechanical Engineering, University of Utah, Salt Lake City, Utah 84112, USA Email: u1377870@utah.edu ORCID: 0000-0003-0575-0217 Associate or Co-investigator Contact Information Name: Chi Zhang Institution: University of Minnesota Address: Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN55455, USA Email: zhan6019@umn.edu ORCID: 0000-0002-2979-5703 Associate or Co-investigator Contact Information Name: Hao Zhou Institution: University of Utah Address: Department of Mechanical Engineering, University of Utah, Salt Lake City, Utah 84112, USA Email: hao.zhou@utah.edu ORCID: Associate or Co-investigator Contact Information Name: Vipul Chaturvedi Institution: University of Minnesota Address: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN55455, USA Email: chatu013@umn.edu ORCID: 0000-0001-6121-4756 Associate or Co-investigator Contact Information Name: Kei Heltemes Institution: University of Minnesota Address: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN55455, USA Email: helte027@umn.edu ORCID: 0000-0003-2983-0772 Associate or Co-investigator Contact Information Name: Hua Zhou Institution: Argonne National Laboratory Address: Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA Email: hzhou@anl.gov ORCID: 0000-0001-9642-8674 Date of data collection (single date, range, approximate date): 20211101 - 20230310 Geographic location of data collection (where was data collected?): University of Minnesota Information about funding sources that supported the collection of the data: This work was primarily supported by the National Science Foundation (NSF) through the UMN MRSEC under DMR-2011401 (Y.Z., W.M.P., C.Z., V.C., K.H., C.L., and X.W.). Parts of this work were carried out at the Characterization Facility, UMN, which receives partial support from the NSF through the MRSEC program. Portions of this work were also conducted in the Minnesota Nano Center, which is supported by the NSF through the National Nanotechnology Coordinated Infrastructure under ECCS-2025124 (Y.Z., W.M.P., C.Z., V.C., K.H., C.L., and X.W.). This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science user facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357 (Hua Z.). The MD and BTE calculations were partially supported by NSF under CBET-2212830 (R.X., Hao Z., and T.F.). The computation used resources of the National Energy Research Scientific Computing Center, supported by the Office of Science of the DOE under Contract DE-AC02-05CH11231 (R.X., Hao Z., and T.F.), the Center for High Performance Computing at the University of Utah, and the Extreme Science and Engineering Discovery Environment. -------------------------- SHARING/ACCESS INFORMATION -------------------------- Suggested Citation: Zhang, Yingying; Postiglione, William M; Xie, Rui; Zhang, Chi; Zhou, Hao; Chaturvedi, Vipul; Heltemes, Kei; Zhou, Hua; Feng, Tianli; Leighton, Chris; Wang, Xiaojia. (2023). Supporting data for Wide-range continuous tuning of the thermal conductivity of La0.5Sr0.5CoO3−δ films via room-temperature ion-gel gating. Retrieved from the Data Repository for the University of Minnesota, https://doi.org/10.13020/kjhp-az69. 1. Licenses/restrictions placed on the data: CC0 2. Links to publications that cite or use the data: https://doi.org/10.48550/arXiv.2303.15545 Zhang, Y., Postiglione, W.M., Xie, R. et al. Wide-range continuous tuning of the thermal conductivity of La0.5Sr0.5CoO3-δ films via room-temperature ion-gel gating. Nat Commun 14, 2626 (2023). https://doi.org/10.1038/s41467-023-38312-z 3. Links to other publicly accessible locations of the data: 4. Links/relationships to ancillary data sets: 5. Was data derived from another source? No --------------------- DATA & FILE OVERVIEW --------------------- Under each top-level file or folder, add description of the data, file formats, software required to open, and any other information (e.g., conditions, filenaming, etc.) to help understand, explain, and navigate the files. 1. File List A. Filename: ncomms_LSCO_source_Alldata_04_14_Final Short description: One excel containing all raw data for plots, including the main paper and the Supplementary XX, following the order of figure numbers. 2. Additional related data collected that was not included in the current data package: No 3. Are there multiple versions of the dataset? No -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: Methods LSCO film growth, device fabrication, and electrolyte gating. Thin films of LSCO were deposited on commercial (MTI corp.) 5 ¡Á 5 mm2 and 10 ¡Á 10 mm2 LaAlO3(001) substrates using high-pressure-oxygen sputtering, from 2¡± polycrystalline sputtering targets of the same nominal stoichiometry. Substrates were first annealed at 900¡ãC in flowing O2 (99.998%, ~1 Torr) for 15 min, before being cooled to 600¡ãC for deposition. LSCO was then deposited via DC sputtering at 600¡ãC in flowing O2 (1.5 Torr) at a power of 60 ??70 W. This produced epitaxial films at a deposition rate of ~20 ?/min. After deposition, films were cooled to RT in 600 Torr of O2 at ~15?oC/min. These procedures essentially employ optimized parameters reported in prior studies6,14-16,30,37. The thicknesses of films in this work varied from 45 to 58 nm, estimated from established growth rates and cross-checked from wide-angle XRD Laue fringe spacings. Sputtered LSCO films were then used to fabricate electrolyte-gate transistor devices6,14,15. As-deposited LSCO films were first Ar-ion milled selectively using steel masks to form LSCO channels of 1 ¡Á 1 mm2. Subsequent Mg(5 nm)/Pt(50 nm) gate and contact electrodes were then sputter-deposited through a separate mask and annealed in O2 (450¡ãC, 5 min). To complete side-gated transistors, a single piece of ion gel was then cut and laminated atop the LSCO channel, contact electrodes (partially), and gate electrodes (substantially). A schematic of the final device is shown in Fig. 1a. The ion gels were fabricated by spin coating (to ?50 ?m thickness) a solution of ionic liquid and polymer onto ~1 inch2 glass wafers. The ionic liquid solution consisted of: 1-ethyl-3-methylimidazolium bis(trifluoro-methylsulfonyl)imide (EMI-TFSI) ionic liquid, poly(vinylidene fluoride-cohexafluoropropylene) polymer, and acetone, in a weight ratio of 1:4:8, respectively. Gating was performed at RT, in vacuum (<1 ¡Á 10?5 Torr), sweeping Vg at 0.5 mV sec?1 to the specified target values; Vg was applied between the side gate pads and two diagonal electrodes shorted to the film channel (see Fig. 1a). During Vg sweeps, two-wire resistance measurements were made in situ between two diagonal electrodes (the two contacts that were not shorted to the gate counter-electrode), representing a source and drain. Such measurements were made by applying a voltage (VSD) of ¡À0.2 V and measuring a current (ISD) (see Supplementary Fig. 2). Vg and VSD were applied with separate Keithley 2400 (K2400) source-measure units, while the gate current (Ig) and ISD were measured with the corresponding K2400 units. After reaching the desired Vg, gating was terminated by disconnecting the voltage supply to the gates, removing the ion gel, and cleaning the film surface with acetone to remove any residual ion gel. X-ray diffraction. LSCO film devices of two dimensions (1 ¡Á 1 mm2 films on 5 ¡Á 5 mm2 substrates, and 4 ¡Á 3.5 mm2 films on 10 ¡Á 10 mm2 substrates) were characterized both before and after gating via high-resolution specular wide-angle XRD (using a Rigaku Smartlab XE, with Cu K¦Á radiation). Reciprocal space mapping was performed with the same instrument and settings. Synchrotron XRD measurements (shown only in Supplementary Fig. 1a) were performed on a representative 4 ¡Á 3.5 mm2 LSCO film deposited on a 10 ¡Á 10 mm2 LAO(001) substrate at the 12-ID-D beamline of the Advanced Photon Source at Argonne National Lab. The synchrotron XRD set-up was equipped with a six-circle Huber goniometer and a Pilatus II 100 K area detector. The spot size and X-ray beam energy were ~500 ¦Ìm and 22 keV (¦Ë ~ 0.56 ?), respectively. The measurements were carried out at a temperature of 150 K with a liquid-N2 gas flow cryocooler. Electronic transport. Four-wire electronic transport measurements were taken in the van der Pauw geometry before and after electrolyte gating of LSCO films (ex situ), to determine the LSCO channel resistivity. Temperature-dependent data were acquired in a Quantum Design Physical Property Measurement System (PPMS). Electronic transport measurements were taken using either quasi-AC with the PPMS internal bridge (for metallic samples), or DC with a Keithley 2400 current source and a Keithley 2002 multimeter (for insulating samples). Determination of VO concentrations, ¦Ä. The oxygen deficiency, ¦Ä, of P-phase LSCO films was estimated using a previously established and validated method14, in which the measured film resistivity is compared to La1-xSrxCoO3 (x ? 0.30) single crystal resistivity data (where ¦Ä is close enough to zero to be considered negligible) to estimate the film ¦Ä. First, the known low-temperature single crystal resistivity is plotted vs. x, then the measured film resistivity is used to interpolate an effective x value, xeff, from this master curve. Using xeff = x - 2¦Ä (i.e., assuming each VO dopes 2 electrons), with x = 0.5 in our case, the film ¦Ä can then be estimated. This estimation can be made only in the P phase, and only up to ¦Ä = 0.25. We do apply this method in the mixed phase region, where the current is expected to be shunted by P regions, but it cannot, therefore, be applied in the BM phase. As noted in connection with Fig. 3c, at Vg = 3, 3.5 and 4 V we simply assume ? ? 0.5 based on the BM structure evident from XRD. TDTR measurements. The thermal conductivities of LSCO films were measured with TDTR49. Prior to TDTR thermal measurements, a ~70 nm Pt layer was sputter-deposited onto the LSCO films (after gating to the desired Vg), to act as a transducer layer for TDTR measurements. At the laser wavelength of 783 nm, the extinction coefficient is ~7.4 for Pt69; therefore, the thickness of 70?nm is sufficient for the Pt transducer to be considered optically opaque. A Si/SiO2 substrate was also coated with Pt in the same deposition, providing a reference to cross-check the electrical and thermal properties of the Pt. In TDTR, a mode-locked Ti:sapphire laser produces a train of optical pulses (~100 fs in duration) at a repetition rate of 80 MHz and a central wavelength of ~780 nm. The laser is divided into a pump beam and a probe beam with two orthogonal polarizations by a polarizing beam splitter. The pump beam is modulated by an electro-optical modulator, which heats the sample. The probe beam is modulated by a mechanical chopper and detects the temperature response of the sample upon pump heating. An objective lens is used to focus the pump and probe beams onto the sample surface. A mechanical delay stage then varies the optical path of the pump beam, which produces a time delay of up to 4 ns between pump heating and probe sensing. The probe beam reflected from the sample is collected with a fast-response Si detector and then amplified by an RF lock-in amplifier for the data reduction. We used a 5¡Á objective lens with a 1/e2 beam spot size of ¡Ö12 ?m for all samples. For temperature-dependent TDTR measurements over the range of ~90 to ~500 K, the sample was mounted on a heating/cooling stage. Specifically, measurements at low temperatures (from ~90 K to RT) were done under vacuum, while measurements at elevated temperatures (from RT to ~500 K) were carried out in air. A MK2000 series temperature controller was used to provide temperature control. The set temperature of the controller was defined as the setting temperature. The laser power was optimized as a compromise between the signal-to-noise ratio and steady-state heating (¦¤Ts) for each set temperature. For measurements at low temperatures, due to the significant decrease in heat capacity, the temperature rise induced by the pump per-pulse can also be large (¦¤Tp). Therefore, we performed a temperature correction for low-temperature measurements, taking into account both ¦¤Ts and ¦¤Tp. The detailed procedures for this temperature correction are provided in Supplementary Section 6. 2. Methods for processing the data: MATLAB and Origin were used for data processing and figure generation. 3. Instrument- or software-specific information needed to interpret the data: The plots in the main paper and Supplementary Information were prepared by Origin. The crystal structures in Fig. 1b were generated by Vesta. 4. Standards and calibration information, if appropriate: All TDTR measurements on the LSCO samples were done after the setup was calibrated by SiO2 reference sample measurements. In this way, the reliability of the TDTR measurements was ensured. 5. Environmental/experimental conditions: All the experiments were done within the temperature range of ~90 to 500 K. 6. Describe any quality-assurance procedures performed on the data: 7. People involved with sample collection, processing, analysis and/or submission: List people and their role. C.L. and X.W. originated and supervised the research. Y.Z. and C.Z. carried out the TDTR measurements and analyses under the guidance of X.W.. W.M.P., V.C., and K.H. prepared the LSCO samples under the guidance of C.L.. W.M.P., V.C., and Hua Z. performed the XRD characterization. W.M.P. fabricated the devices and performed the electrolyte gating and electrical transport measurements and analyses, under the guidance of C.L.. R.X., Hao Z., and T.F. did the MD simulations and BTE calculations. Y.Z., W.M.P., R.X., T.F., C.L., and X.W. contributed to the writing of the manuscript. All authors discussed the data and provided input on the paper. ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: Natcommun_LSCO_source_Alldata_04_14_2023_Final ----------------------------------------- Contains 12 worksheets, one for each figure: Figure 1c Figure 1d Figure 2b Figure 3a Figure 3b Figure 3c Figure 3d Figure 3e Figure 4a Figure 4b Figure S1a Figure S1b 1. Number of variables: Information is detailed in the excel spreadsheet, figure plots, and figure captions. 2. Number of cases/rows: Information is detailed in the excel spreadsheet, figure plots, and figure captions. 3. Variable List Information is detailed in the excel spreadsheet, figure plots, and figure captions.