Labram hr spectrometer

After crystallization, the resulting biomorphic precipitates are extracted out of the growth cassette and then analyzed by X-ray diffraction (Bruker D8 Venture, Cu K_α). In all cases and for all temperatures the precipitates are composed of monohydrocalcite (Supplementary Fig. 3). The crystallization at 45 and 60 °C are also analyzed by time-lapse measurements at different growth stages (12, 24, and 48 h) by in situ Raman microspectroscopy with a wavelength of 532 nm (LabRAM-HR spectrometer, Jobin-Yvon, Horiba, Japan). All the spectra collected from the biomorphic aggregates under these temperatures exhibit clear bands at 696, 719, and 1067 cm⁻¹ (Supplementary Fig. 4), which correspond to the characteristic peaks of the carbonate group in monohydrocalcite. In addition, the sea urchin-like heterotextured architectures formed by stepwise adjustment of temperature of growth (25–70 °C) are also identified as monohydrocalcite by X-ray diffraction (Supplementary Fig. 3).

The P-XRD analysis employed Cu Ka radiation and was conducted using the X Pert PRO X-ray Diffraction instrument. The SEM and EDX studies were investigated using a JEOL JSM-6510LA electron microscope, while a JEOL Model JEM1400 instrument was used for the TEM study. The materials were synthesized using a HD150 PAD model Muffle Furnace, and the Autolab PGSTAT204 FRA32M was utilized to carry out CV and DPV studies. The Raman spectra were obtained from various locations of the sample using a Jobin Yvon LabRam HR spectrometer equipped with Ar laser 632 nm. XPS measurements were conducted via Omicron spectrometer with Al Ka as the X-ray source (1486.6 eV) to examine the atomic ratio of the elements and determine the corresponding elemental composition of the samples.

The optical images were taken using a Nikon microscope. SEM images were obtained using a LEO-1530 microscope (LEO Electron Microscopy. GERMANY). Raman spectra were collected with a HORIBA Lab RAM HR spectrometer (514 nm laser excitation) (HORIBA Jobin Yvon. FRANCE). Raman mapping images were recorded by a Raman 11 spectroscopy (Nanophonon. JAPAN). AFM images were acquired by a SPM-960 instrument (SHIMADZU. JAPAN). The transmission spectra of graphene were obtained with a UV-visible spectrophotometer.

PL properties of NGO single crystals and thin films were studied by exciting with the 325 nm line of a He-Cd laser with a spot size of ~800 nm and a power of 10 mW, (laser intensity ~1.5 MW/cm²) and recorded using a JY-Horiba LabRAM HR spectrometer. Further elemental composition, valence and structural analyses were done using Rutherford backscattering spectroscopy ((using 3.5 Mev singletron accelerator)), secondary ion mass spectroscopy (using ToF-SIMS-IV from ION-TOF GmbH), x-ray photoelectron spectroscopy (using Axis Ultra Delay Line Detector from Kratos Analytical) and x-ray diffraction (using Empyrean powder XRD system from PANalytical).

The structural features of the as-prepared samples were investigated by scanning electron microscopy (SEM) using a FEI Quanta 3D FEG instrument. Energy-dispersive x-ray spectroscopy (EDAX) analysis was performed on an Apollo XL instrument fitted with a Quanta 3D-5 Microscope (Port: EDAX). Transmission electron microscopy (TEM) was performed using a JEOL, JEM 3010 instrument (300 kV) fitted with a GATAN CCD camera. The powder x-ray diffraction (PXRD) patterns were recorded on a Bruker AXS, D8 Discover x-ray diffractometer using Cu Kα irradiation (λ = 1.54187 Å) in a 2θ range from 15 to 90°. A TGA 850C, Mettler Toledo thermogravimetric analyzer was used to evaluate the weight loss on heating. 10 mg of the sample was heat-treated in a ceramic crucible from 30 to 900 °C at a constant heating rate of 5 °C min⁻¹ under a N₂ atmosphere (flow rate of 40 mL min⁻¹). To study the surface properties, x-ray photoelectron spectroscopy (XPS, VG Scientific ESCA LAB V) was used. Raman spectroscopy was performed at different locations of the sample using a Jobin Yvon LabRam HR spectrometer with a 514.5 nm Ar laser. N₂ and O₂ adsorption studies were performed at a 77 K temperature using a QUANTACHROME QUADRASORB SI analyzer and an AUTOSORB IQ2 instrument. Prior to the adsorption studies, all the samples were kept at 200 °C under high vacuum for 12 h.