Raman-Spectrometer; Jobin-Yvon T64000 Triple-Monochromator, Horiba
The triple-grating Horiba T64000 Raman spectrometer coupled with a Symphony LN2-cooled charge-coupled device (CCD) detector and an Olympus BH41 confocal microscope can be used for the determination of the crystal structure and chemical composition of inorganic and organic crystalline and amorphous solids as well as fluids, whereas the resulting Raman spectra are structural fingerprints by which various molecules can be identified. The advantage of Raman spectroscopy over other analytical methods is fourfold: (a) it is truly non-destructive, contactless and preparation-free method, (b) it covers the whole spectral range (15-6000 cm-1) compared with FTIR spectroscopy, (c) it can detect light-element containing (organic and H-bearing) compounds, and (d) the usage of a microscope enables beam focusing down to 1-2 μm and thus the non-problematic analysis also of rough surfaces.
The general setup of the microscope does not allow the analysis of objects thicker than ~ 3-3.5 cm. By measuring with the 50x LWD objective, the interaction spot dimensions of the laser with the sample surface are ~ 2 μm, while the average measuring time can not straightforwardly be calculated as it depends on the analysed sample. However, in most of the cases, a minimum of 5 sec/loop for the 15-3800 cm-1 spectral range is needed which translates in 2 min for each measurement. For instance, line profiles on marble cross-sections with the 514.5 nm laser: ~ 2.5-3 min with data acquisition time set to 11-15 sec/loop and spectral range between 15 and 1800 cm-1.
- General description: Triple-grating Horiba T64000 Raman spectrometer with a confocal BH41 microscope and lasers operating at 8 different wavelengths between 514.5 and 244 nm.
- Application aim: Determination of the crystal structure and chemical composition of inorganic and organic crystalline and amorphous solids as well as of fluids
- Mobility: stationary ca. 400 kg (power supply, laser heads, ICE, and monochromator system)
- Equipment specifics:
- Coherent Innova 90C FreD Ar+ laser emitting at 514.5, 488.0, 457.5, 363.8, 257.2 and 244.0 nm, operating at max. 2000, 1500, 350, 140, 100 and 100 mW, respectively
- Air-cooled IK Kimmon Koha He-Cd laser emitting at 441.6 or 325.0 nm and operating at max. 300 and 200 mW, respectively
- Air-cooled REO He-Ne laser emitting at 633 nm and operating at max. 35 mW
- Gratings are 1800 and 2400 (for the Coherent laser)
- Power consumption of ca. 1.5 kW/h (for the Coherent laser)
- The Coherent laser is water-cooled and connected to the Coherent Innova Integrated Cooling Exchanger (ICE): water temperature range is 5-30oC
- LN2-cooled Symphony CCD detector with 15-6000 cm-1 spectral range
- Olympus BX41 confocal microscope equipped also with a 50x Long Working Distance (LWD) objective with numerical aperture = 0.5
- Spectral resolution: 2 cm-1
- Instrumental peak position accuracy: 0.35 cm-1
- 2D mapping via a Märzhäuser Wetzlar motorised XYZ-stage, joystick-controlled with travel range in x- and y-direction: 5.0 x 7.5 cm
- Application requirements: dark room, LN2 supply and air conditioner, 18-25oC and relative humidity ≤ 80%
- Sample required: no, analysed object no thicker than ~3 cm
- Interaction spot dimensions: 2 μm with the 50x objective
- Contact required: no
- Limitations:
- Impact of photoluminescence of some samples should be taken into account and metallic samples do not produce a strong Raman scattering.
- Set up time: ca. 45 min for warming up the laser and calibration against a silicon standard wafer (peak at 520.5 cm-1)
- Average processing time: a couple of min/spectrum (depends on the complexity of the sample)
- Software package: LabSpec 5 Spectroscopy Software Suite operating in Windows XP
- Output: .ngs (~ 10 KB) or .txt (~ 40-50 KB)
- Evaluation program: OriginPro 2019b
- Contact: Stelios Aspiotis, stylianos.aspiotis"AT"uni-hamburg.de
- Location of the equipment: Mineralogisch-Petrographisches Institut, MPI, (Grindelallee 48, Hamburg)