scholarly journals Orientation Identification of the Black Phosphorus with Different Thickness Based on B2g Mode Using a Micro-Raman Spectroscope under a Nonanalyzer Configuration

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5572
Author(s):  
Rubing Li ◽  
Yongchao Shang ◽  
Huadan Xing ◽  
Xiaojie Wang ◽  
Mingyuan Sun ◽  
...  

As an anisotropic material, the unique optoelectronic properties of black phosphorus are obviously anisotropic. Therefore, non-destructive and fast identification of its crystalline orientation is an important condition for its application in optoelectronics research field. Identifying the crystalline orientation of black phosphorus through Ag1 and Ag2 modes under the parallel polarization has high requirements on the Raman system, while in the nonanalyzer configuration, the crystalline orientation of the thick black phosphorus may not be identified through Ag1 and Ag2 modes. This work proposes a new method to identify the crystalline orientation of black phosphorus of different thicknesses. This method is conducted under the nonanalyzer configuration by B2g mode. The results show that B2g mode has a good consistency in the identification of crystalline orientations. In this paper, a theoretical model is established to study the angle-resolved Raman results of B2g mode. The new method can accurately identify the crystalline orientation with different layers of black phosphorus without misidentification.

1998 ◽  
Vol 545 ◽  
Author(s):  
X. Sun ◽  
Z. Zhang ◽  
G. Dresselhaus ◽  
M. S. Dresselhaus ◽  
J. Y. Ying ◽  
...  

AbstractBismuth as a semimetal is not a good thermoelectric material in bulk form because of the approximate cancellation between the electron and hole contributions. However, quantum confinement can be introduced by making Bi nanowires to move the lowest conduction subband edge up and the highest valence subband edge down to get a one-dimensional (1D) semiconductor at some critical wire diameter dc. A theoretical model based on the basic band structure of bulk Bi is developed to predict the dependence of these quantities on wire diameter and on the crystalline orientation of the bismuth nanowires. Numerical modeling is performed for trigonal, binary and bisectrix crystal orientations. By carefully tailoring the Bi wire diameter and carrier concentration, substantial enhancement in the thermoelectric figure of merit is expected for small nanowire diameters.


Nanoscale ◽  
2021 ◽  
Author(s):  
Yong Kang ◽  
Zhengjun Li ◽  
Fengying Lu ◽  
Zhiguo Su ◽  
Xiaoyuan Ji ◽  
...  

Two dimensional black phosphorus nanosheets (BP NS) have attracted plenty of attentions in the research field of cancer photonic therapy. However, the poor stability and relatively low efficiency in reactive...


1979 ◽  
Vol 111 (8) ◽  
pp. 875-882
Author(s):  
A. G. Raske ◽  
M. Alvo

AbstractSample sizes needed to measure population levels of the birch casebearer, Coleophora fuscedinella Zeller, and its damage to white birch, Betula papyrifera Marsh, were calculated for various degrees of confidence and assurance. Both a non-destructive and a destructive sampling plan are presented and a new method to classify the damage level of a stand. This method uses a maximum likelihood technique to estimate the proportion of trees of various damage classes.


ChemPhysChem ◽  
2017 ◽  
Vol 18 (20) ◽  
pp. 2826-2826
Author(s):  
Tianyu Wang ◽  
Jing Liu ◽  
Biao Xu ◽  
Ridong Wang ◽  
Pengyu Yuan ◽  
...  

1994 ◽  
Vol 04 (02n03) ◽  
pp. 165-179 ◽  
Author(s):  
K. SERA ◽  
S. FUTATSUGAWA ◽  
S. HATAKEYAMA ◽  
S. SAITOU

A new method has been developed to determine absorption curves which are needed to derive quantitative values in PIXE analysis. In this method two spectra obtained with absorbers of different thickness are divided by each other after background subtraction and the absorption curve can be obtained immediately. Absorption curves for a 50 and a 200 µm-thick Mylar films and that for a Cr foil of 2500 µg/cm2 were determined experimentally. These curves are in good agreement with the absorption values derived from peak areas of characteristic x-rays. This method enables one to obtain absorption curves for any kind of absorber accurately and quickly.


1999 ◽  
Vol 5 (6) ◽  
pp. 609-618
Author(s):  
M. Stacheder ◽  
G. Grassegger ◽  
F. Grüner

Abstract A new commercially available dielectric technique for the non-destructive determination of moisture in building materials based on the principle of 'time-domain reflectometry' (TDR) is presented. TDR measurements on samples of sandstone, brick, concrete and floor cover matched very well with results of conventional moisture measuring methods such as oven-drying or calciumcarbide-technique. The new method showed only a low influence of salt content or surface moisture of the material on the results.


2015 ◽  
Vol 112 (15) ◽  
pp. 4523-4530 ◽  
Author(s):  
Xi Ling ◽  
Han Wang ◽  
Shengxi Huang ◽  
Fengnian Xia ◽  
Mildred S. Dresselhaus

One hundred years after its first successful synthesis in the bulk form in 1914, black phosphorus (black P) was recently rediscovered from the perspective of a 2D layered material, attracting tremendous interest from condensed matter physicists, chemists, semiconductor device engineers, and material scientists. Similar to graphite and transition metal dichalcogenides (TMDs), black P has a layered structure but with a unique puckered single-layer geometry. Because the direct electronic band gap of thin film black P can be varied from 0.3 eV to around 2 eV, depending on its film thickness, and because of its high carrier mobility and anisotropic in-plane properties, black P is promising for novel applications in nanoelectronics and nanophotonics different from graphene and TMDs. Black P as a nanomaterial has already attracted much attention from researchers within the past year. Here, we offer our opinions on this emerging material with the goal of motivating and inspiring fellow researchers in the 2D materials community and the broad readership of PNAS to discuss and contribute to this exciting new field. We also give our perspectives on future 2D and thin film black P research directions, aiming to assist researchers coming from a variety of disciplines who are desirous of working in this exciting research field.


2021 ◽  
Author(s):  
◽  
Amandine Chambord

<p>Quantifying past motions of tectonic plates in the southwest Pacific is important because the Pacific-Antarctic ridge is the only non-destructive boundary between the Pacific plate and other major plates. However, formation of sea-ice near Antarctica impairs the collection of magnetic anomaly data that are necessary to calculate plate rotations. A detailed analysis of all ship-track magnetic data available in the southwest Pacific (61 cruises, 153 profiles, including several cruises collected after 1995) is presented here. Four different sources of uncertainty are quantified: (1) confidence of magnetic anomaly identification, (2) magnetic reversal location picking precision, (3) ship navigation precision, and (4) magnetic data quality. Finite plate rotations are calculated for the southwest Pacific (42.5 to 79 Ma) using the resulting magnetic anomaly database (1528 magnetic reversal data). Finite rotations were calculated using the Hellinger criterion, or by a new method presented here that assumes orthogonality between fracture zones and ridge segments. The new method requires less parameters and is hence able better estimate rotations in cases with an uneven distribution of sparse magnetic data. Rotations and formal uncertainties are calculated for thirty-one chrons (c20y to c33o). They confirm the existence of a three plate system (Pacific, Marie Byrd Land, Bellingshausen) in the southwest Pacific from before c31o (68.7 Ma) until c28y (62.5 Ma). After c28y, the Bellingshausen and Marie Byrd Land plates moved as a single plate.</p>


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