1. ABOUT THE DATASET -------------------- Title: Creator(s): Charles Parton Barr[1], Helen F. Gleeson[1], Richard J. Mandle [1,2] Organisation(s): 1. School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK, 2. School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK Rights-holder(s):Unless otherwise stated, Copyright 2023 University of Leeds Publication Year: 2024 Description: Dataset for the article "Room-temperature ferroelectric nematic liquid crystal showing a large and diverging density". The dataset contains: 1. Temperature-dependent density measurements for the liquid crystals 5CB, 8CB, CCU3F, NCSPCH6 and M5. The density was measured on using an Anton-Paar DMA4100M densitometer. The data consists of measurements of density at set temperature intervals 2. Differential scanning calorimetry measurements for the liquid crystals 5CB, 8CB, CCU3F, NSCPCH6 and M5. Temperature dependent scans were performed using a TA Instruments Q2000 DSC with data providing heat-flow scans from which the thermodynamic calculations are performed 3. Temperature-dependent polarisation measurements of the liquid crystal DIO gathered using the current reversal technique. The measurements consist of the record current through a cell filled with DIO 4. Measurements of the ordinary and extraordinary refractive indices of M5. The refractive indices were measured on a Bellingham+Stanley Abbe 60/DR refractometer. Cite as: [Parton-Barr, Charles; Gleeson, Helen F.; Mandle, Richard J; (2024) Dataset for "Room-temperature ferroelectric nematic liquid crystal showing a large and diverging density.". University of Leeds. [Dataset] https://doi.org/10.1039/1466 Related publication: Parton-Barr, C., Gleeson, H. F., & Mandle, R. J. (2024). Room-temperature ferroelectric nematic liquid crystal showing a large and diverging density. Soft Matter, 2(3), 672–68. https://doi.org/10.1039/d3sm01282d Contact: r.mandle@leeds.ac.uk 2. TERMS OF USE --------------- Copyright 2024 University of Leeds [A standard copyright notice and licence statement with URL can be used, e.g. Copyright [publication year] [University of Leeds, name of other rights-holder(s)]. Unless otherwise stated, 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: Developing a tuneable ferroelectric nematic surface Dates: 01/11/2022 - 01/05/2026 Funding organisation: University of Leeds; UKRI Grant no.: N/A; MR/W006391/1, 4. CONTENTS ----------- File listing dataset/densities: .xls files of density measurements with their names identifying which liquid crystal they represent - Unique sample Id: Identification for the sample measurement - Date: date of measurement - Time: Time of measurement - Density: measured density of sample (g/cm3) - Specific gravity: specific gravity of sample - Density temperature (C) Temperature measurement took place - Master condition: Instrument status - Density (not visc.-corr.): Measured density of sample without viscosity corrections - Camera image: any attached camera image dataset/dsc/X: X = name of liquid crystal. directory contains X.001 and X.mth files which the universal analysis software package is used to analyse thermograms dataset/polarisation/DIO_polarisation_5v/current_response_figures/dio_[MEASUREMENT_VOLTAGE]_[MEASUREMENT_TEMPERATURE_C]: png images used to select the boundaries for the current reversal peak dataset/polarisation/DIO_[TEMP]_[CELL_GAP]_[ALIGNMENT]_[VOLTS]_[SIG_FREQ].dat: current response measurements analysed in the spon_ui.py python package dataset/refractive_indices/M5.xls: refractive indices measurements of M5 - TEMP: measurement temperature ordinary refractive indices - 1d: 1st measurement with the measurement band descending - 2u: 2nd measurement with the measurement band ascending - 3u: 3rd measurement with the measurement band descending - avg: average of the measurements - refractive index: refractive index conversion - 1d: 1st measurement with the measurement band descending - 2u: 2nd measurement with the measurement band ascending - 3u: 3rd measurement with the measurement band descending - avg: average of the measurements - refractive index: refractive index conversion - birefringence: birefringence calculation 5. METHODS ---------- 1. Dataset/densities - Density measurements were performed using an Anton-Paar DMA 4100M densitometer which operates on the oscillating U-tube principle. A U-shaped borosilicate glass tube is filled with approx. 1 mL material. Samples were loaded using a SGE precision syringe. A syringe heater was used for samples with above-ambient melting points; the syringe outlet was interfaced with the DMA 4100M inlet port using a short section of PTFE tubing with appropriate PEEK/ETFE microfluidic connectors. The presence of bubbles within the tube was assessed through visual inspection. A temperature scan is then performed taking measurements at intervals over a temperature range measuring density. Measurements were performed between 02/12/2022-11/05/2023 at the University of Leeds 2. Dataset/dsc - Differential scanning calorimetry measurements were performed using a TA instruments Q2000. A TZERO DSC pan is prepared with less than 10mg of material and placed onto a thermocouple. Heat flow thermogram scans are performed over a set temperature range and the DSC curves are recorded. Scans were performed between 02/06/23-04/07/23. M5 measurements were performed by Diana Nikolova 3. Dataset/polarisation - Polarisation measurements were performed using the current reversal technique which measures the current response to switching of the polarisation. A triangular wave voltage with VRMS = 5 V and frequency = 63 Hz was produced by an Agilent 33220A waveform generator and applied to DIO in a 4 mm INSTEC cell with no alignment layer. Temperature control was achieved with a LINKAM THM600 hot stage. The output signal was recorded on RIGOL DHO 4204 oscilloscope. Integration of the current response peaks calculates the total spontaneous polarisation. The presented measurements were performed on 15/11/2023 at the University of Leeds 4. Dataset/refractive_indices Refractive indices measurements were performed on a Bellingham + Stanley Abbe 60/DR refractometer. The refractometer finds the critical angle of total reflection of an LC sample at a wavelength of 589 nm. A polariser is used to differentiate between the ordinary and extraordinary refractive indices. temperature control is achieved by circulating water with a temperature range from room temperature to approx 70C and an accuracy of 0.2 C. The presented measurements were performed on 19/12/2023 at the University of Leeds