Observation of the out-of-plane mode in the Raman scattering from the graphite edge plane

1999 ◽  
Vol 59 (1) ◽  
pp. 62-64 ◽  
Author(s):  
Yasushi Kawashima ◽  
Gen Katagiri
MRS Advances ◽  
2017 ◽  
Vol 2 (29) ◽  
pp. 1539-1544 ◽  
Author(s):  
Katarzyna Gołasa ◽  
Magdalena Grzeszczyk ◽  
Maciej R. Molas ◽  
Małgorzata Zinkiewicz ◽  
Karol Nogajewski ◽  
...  

ABSTRACTThe effect of temperature (5K to 300K) on the Raman scattering due to A1g/A1’ modes associated with the out-of-plane vibrations in bilayer (2L) and trilayer (3L) MoTe2 is investigated. The temperature evolution of the modes critically depends on the flake thickness. The A1g mode intensity in 2L MoTe2 observed with λ=632.8 nm light excitation decreases with decreasing temperature down to 220K and the mode vanishes from the Stokes scattering spectrum in the temperature range between 160K and 220K. The peak recovers at lower temperatures and at T=5K it becomes three times more intense that at room temperature. Similar non-monotonic intensity evolution is observed for the A1’ mode in 3L MoTe2 in which tellurium atoms in all three layers vibrate in-phase. On the contrary, the intensity of the other out-of-plane Raman-active mode in which vibrations of tellurium atoms in the central layer of 3L MoTe2 are shifted by 180° with respect to vibrations in outer layers, only weakly depends on temperature.The observed quenching of the out-of-plane modes in the Raman scattering in thin MoTe2 layers is related to the destructive interference of the resonant- and the non-resonant contributions to the Raman scattering. The resonance with the M point of the Brillouin zone in few-layers of MoTe2 is considered. Effects related to the resonant quenching of the in-phase out-of-plane mode are discussed.


Nanophotonics ◽  
2017 ◽  
Vol 6 (6) ◽  
pp. 1281-1288 ◽  
Author(s):  
Katarzyna Gołasa ◽  
Magda Grzeszczyk ◽  
Maciej R. Molas ◽  
Małgorzata Zinkiewicz ◽  
Łukasz Bala ◽  
...  

AbstractTemperature-dependent (5 K–300 K) Raman scattering study of A1g/A′1 phonon modes in mono-layer (1L), bilayer (2L), trilayer (3L), and tetralayer (4L) MoTe2 is reported. The temperature evolution of the modes’ intensity critically depends on the flake thickness. In particular with λ=632.8-nm light excitation, a strongly non-monotonic dependence of the A1g mode intensity is observed in 2L MoTe2. The intensity decreases with decreasing temperature down to 220 K, and the A1g mode almost completely vanishes from the Stokes scattering spectrum in the temperature range between 160 K and 220 K. The peak recovers at lower temperatures, and at T=5 K, it becomes three times more intense that at room temperature. Similar non-monotonic intensity evolution is observed for the out-of-plane mode in 3L MoTe2 in which tellurium atoms in all three layers vibrate in-phase. The intensity of the other out-of-plane Raman-active mode (with vibrations of tellurium atoms in the central layer shifted by 180° with respect to the vibrations in outer layers) only weakly depends on temperature. The observed quenching of the Raman scattering in 2L and 3L MoTe2 is attributed to a destructive interference between the resonant and non-resonant contributions to the Raman scattering amplitude. The observed “antiresonance” is related to the electronic excitation at the M point of the Brillouin zone in few-layer MoTe2.


1983 ◽  
Vol 2 (3-4) ◽  
pp. 125-135 ◽  
Author(s):  
J. J. F. Ramaekers ◽  
L. B. Krijnen ◽  
H. J. Lips ◽  
J. Langelaar ◽  
R. P. H. Rettschnick

s-Tetrazine argon complexes T−Arn (n = 1, 2) are formed in a supersonic expansion of argon seeded with s-tetrazine. The expansion was conducted through a nozzle of 50 or 100 μm with an argon stagnation pressure between 1 and 1.5 bar. From spectrally resolved measurements it is clear that vibrational redistribution processes as well as vibrational predissociation processes take place after SVL excitation within the complex.From rise and decay time experiments it can be concluded, that after excitation of the 6a1 complex level, the above mentioned processes are consecutive and not parallel. It appears that the out of plane mode 16a couples with the Van der Waals stretching mode. The predissociation rate of the 16a2 complex is observed to be 2.3 × 109 s−1.


Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1067
Author(s):  
Hilmi Artun Oyman ◽  
Baris Can Efe ◽  
Mustafa Akin Icel ◽  
Yigit Daghan Gokdel ◽  
Onur Ferhanoglu ◽  
...  

A micro-scanner made of stainless-steel is fabricated via laser cutting technology for 3D Lissajous confocal imaging. The multi-gimbaled structure of the device provides two orthogonal torsional modes and three different out-of-plane modes. Torsional modes can be used to achieve 2D scan and all of the out-of-plane modes can be used in changing the focus of the micro-scanner to achieve a 3D scanning pattern. One of the out-of-plane modes along with two orthogonal torsional modes can be employed for scanning a large depth-stack in sparse fashion while another out-of-plane mode can satisfy a much higher scan fill-rate with less field of view (FOV). Simulations of the micro-scanner are obtained using finite element method (FEM) software and compared with the characterization data gathered from Laser Doppler Vibrometer (LDV). Using various out-of-plane modes, the constructed fill patterns are simulated on MATLAB and fill rates compared.


2002 ◽  
Vol 8 (3) ◽  
pp. 337-387 ◽  
Author(s):  
Ali H. Nayfeh ◽  
Haider N. Arafat ◽  
Char-Ming Chin ◽  
Walter Lacarbonara

We investigate the nonlinear nonplanar responses of suspended cables to external excitations. The equations of motion governing such systems contain quadratic and cubic nonlinearities, which may result in two-to-one and one-to-one internal resonances. The sag-to-span ratio of the cable considered is such that the natural frequency of the first symmetric in-plane mode is at first crossover. Hence, the first symmetric in-plane mode is involved in a one-to-one internal resonance with the first antisymmetric in-plane and out-of-plane modes and, simultaneously, in a two-to-one internal resonance with the first symmetric out-of-plane mode. Under these resonance conditions, we analyze the response when the first symmetric in-plane mode is harmonically excited at primary resonance. First, we express the two governing equations of motion as four first-order (i.e., state-space formulation) partial-differential equations. Then, we directly apply the methods of multiple scales and reconstitution to determine a second-order uniform asymptotic expansion of the solution, including the modulation equations governing the dynamics of the phases and amplitudes of the interacting modes. Then, we investigate the behavior of the equilibrium and dynamic solutions as the forcing amplitude and resonance detunings are slowly varied and determine the bifurcations they may undergo.


2010 ◽  
Vol 18 (9) ◽  
pp. 8800 ◽  
Author(s):  
M. Sathish Kumar ◽  
Xianji Piao ◽  
Sukmo Koo ◽  
Sunkyu Yu ◽  
Namkyoo Park

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Lianhua Wang ◽  
Yueyu Zhao ◽  
Giuseppe Rega

The large amplitude vibration and modal interactions of shallow suspended cable with three-to-three-to-one internal resonances are investigated. The quasistatic assumption and direct approach are used to obtain the condensed suspended cable model and the corresponding modulation equations for the case of primary resonance of the third symmetric in-plane or out-of-plane mode. The equilibrium, periodic, and chaotic solutions of the modulation equations are studied. Moreover, the nonplanar motion and symmetric character of out-of-plane vibration of the shallow suspended cables are investigated by means of numerical simulations. Finally, the role played by the quasistatic assumption, internal resonance, and static configuration in disrupting the symmetry of the out-of-plane vibration is discussed.


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