scholarly journals Single‐shot single‐voxel lactate measurements using FOCI‐LASER and a multiple‐quantum filter

2015 ◽  
Vol 28 (4) ◽  
pp. 496-504 ◽  
Author(s):  
Geoffrey S. Payne ◽  
Nandita M. deSouza ◽  
Christina Messiou ◽  
Martin O. Leach
Keyword(s):  
Multiple Quantum ◽  
Single Shot ◽  
Single Voxel

Characterisation of multilayer materials using a position-sensitive atom probe

1990 ◽  
Vol 48 (4) ◽  
pp. 624-625
Author(s):  
RAD Mackenzie ◽  
G D W Smith ◽  
A. Cerezo ◽  
J A Liddle ◽  
CRM Grovenor ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Spatial Information ◽  
Chemical Vapour ◽  
Atom Probe ◽  
Organic Chemical ◽  
Growth Stages ◽  
Multiple Quantum ◽  
Quartz Wool ◽  
Position Sensitive

The position sensitive atom probe (POSAP), described briefly elsewhere in these proceedings, permits both chemical and spatial information in three dimensions to be recorded from a small volume of material. This technique is particularly applicable to situations where there are fine scale variations in composition present in the material under investigation. We report the application of the POSAP to the characterisation of semiconductor multiple quantum wells and metallic multilayers.The application of devices prepared from quantum well materials depends on the ability to accurately control both the quantum well composition and the quality of the interfaces between the well and barrier layers. A series of metal organic chemical vapour deposition (MOCVD) grown GaInAs-InP quantum wells were examined after being prepared under three different growth conditions. These samples were observed using the POSAP in order to study both the composition of the wells and the interface morphology. The first set of wells examined were prepared in a conventional reactor to which a quartz wool baffle had been added to promote gas intermixing. The effect of this was to hold a volume of gas within the chamber between growth stages, leading to a structure where the wells had a composition of GalnAsP lattice matched to the InP barriers, and where the interfaces were very indistinct. A POSAP image showing a well in this sample is shown in figure 1. The second set of wells were grown in the same reactor but with the quartz wool baffle removed. This set of wells were much better defined, as can be seen in figure 2, and the wells were much closer to the intended composition, but still with measurable levels of phosphorus. The final set of wells examined were prepared in a reactor where the design had the effect of minimizing the recirculating volume of gas. In this case there was again further improvement in the well quality. It also appears that the left hand side of the well in figure 2 is more abrupt than the right hand side, indicating that the switchover at this interface from barrier to well growth is more abrupt than the switchover at the other interface.

FEMTOSECOND SPECTRAL HOLE-BURNING IN GaAs/AlGaAs MULTIPLE QUANTUM WELLS

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-511-C5-515 ◽  
Author(s):  
J. L. OUDAR ◽  
J. DUBARD ◽  
F. ALEXANDRE ◽  
D. HULIN ◽  
A. MIGUS ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Multiple Quantum Wells ◽  
Hole Burning ◽  
Spectral Hole Burning ◽  
Multiple Quantum ◽  
Spectral Hole

RESONANT TUNNELING STUDIES OF VARIABLY SPACED MULTIPLE QUANTUM WELL STRUCTURES IN THE AlGaAs SYSTEM

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-457-C5-461
Author(s):  
C. J. SUMMERS ◽  
K. F. BRENNAN ◽  
A. TORABI ◽  
H. M. HARRIS ◽  
J. COMAS
Keyword(s):  
Quantum Well ◽  
Resonant Tunneling ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Quantum Well Structures

FAR INFRARED MAGNETO-ABSORPTION STUDY OF BARRIER IMPURITIES AND SCREENING IN GaAs/AlGaAs MULTIPLE QUANTUM WELLS

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-239-C5-242 ◽  
Author(s):  
E. GLASER ◽  
B. V. SHANABROOK ◽  
R. J. WAGNER ◽  
R. L. HAWKINS ◽  
W. J. MOORE ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Far Infrared ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Absorption Study
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