Type of material Spectroscopy

1 type of material

1.1 atoms
1.2 molecules
1.3 crystals , extended materials
1.4 nuclei

type of material

spectroscopic studies designed radiant energy interacts specific types of matter.

atoms

atomic spectroscopy first application of spectroscopy developed. atomic absorption spectroscopy (aas) , atomic emission spectroscopy (aes) involve visible , ultraviolet light. these absorptions , emissions, referred atomic spectral lines, due electronic transitions of outer shell electrons rise , fall 1 electron orbit another. atoms have distinct x-ray spectra attributable excitation of inner shell electrons excited states.

atoms of different elements have distinct spectra , therefore atomic spectroscopy allows identification , quantitation of sample s elemental composition. robert bunsen , gustav kirchhoff discovered new elements observing emission spectra. atomic absorption lines observed in solar spectrum , referred fraunhofer lines after discoverer. comprehensive explanation of hydrogen spectrum success of quantum mechanics , explained lamb shift observed in hydrogen spectrum, further led development of quantum electrodynamics.

modern implementations of atomic spectroscopy studying visible , ultraviolet transitions include flame emission spectroscopy, inductively coupled plasma atomic emission spectroscopy, glow discharge spectroscopy, microwave induced plasma spectroscopy, , spark or arc emission spectroscopy. techniques studying x-ray spectra include x-ray spectroscopy , x-ray fluorescence (xrf).

molecules

the combination of atoms molecules leads creation of unique types of energetic states , therefore unique spectra of transitions between these states. molecular spectra can obtained due electron spin states (electron paramagnetic resonance), molecular rotations, molecular vibration , electronic states. rotations collective motions of atomic nuclei , typically lead spectra in microwave , millimeter-wave spectral regions; rotational spectroscopy , microwave spectroscopy synonymous. vibrations relative motions of atomic nuclei , studied both infrared , raman spectroscopy. electronic excitations studied using visible , ultraviolet spectroscopy fluorescence spectroscopy.

studies in molecular spectroscopy led development of first maser , contributed subsequent development of laser.

crystals , extended materials

the combination of atoms or molecules crystals or other extended forms leads creation of additional energetic states. these states numerous , therefore have high density of states. high density makes spectra weaker , less distinct, i.e., broader. instance, blackbody radiation due thermal motions of atoms , molecules within material. acoustic , mechanical responses due collective motions well. pure crystals, though, can have distinct spectral transitions, , crystal arrangement has effect on observed molecular spectra. regular lattice structure of crystals scatters x-rays, electrons or neutrons allowing crystallographic studies.

nuclei

nuclei have distinct energy states separated , lead gamma ray spectra. distinct nuclear spin states can have energy separated magnetic field, , allows nmr spectroscopy.