Effect of annealing on the temperature-dependent dielectric properties of LaAlO3 at terahertz frequencies

Xingquan Zou, Mi He, Daniel Springer, Dongwook Lee, Saritha K. Nair, Siew Ann Cheong, Tom Wu, C. Panagopoulos, D. Talbayev, and Elbert E. M. Chia

Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore 

Department of Physics and Engineering Physics, 2001 Percival Stern Hall, 6400 Freret street, New Orleans, Louisiana 70118, USA  

AIP Advances 2, 012120 (2012); http://dx.doi.org/10.1063/1.3679725

Abstract

We present THz conductivity of LaAlO3 (LAO) as a function of temperature and annealing, using terahertz time-domain spectroscopy (THz-TDS). We observed that, after annealing, spectral weight redistribution occurs, such that the real conductivity σ1(ω) changed from a featureless and almost frequency-independent spectrum, into one where peaks occur near the phonon frequencies. These phonon frequencies increase with increasing temperature. We attribute the appearance of these absorption peaks to the diffusion and relocation of oxygen vacancies. The dielectric functions of annealed LAO are well fitted with the Drude-Lorentz model.

from the paper

"........Our work fills this gap in knowledge, enabling future researchers to use the temperature-dependent refractive index of LAO to characterize their thin films more accurately. Here we report the temperature-dependent (10 K ‐ 300 K) dielectric response of LAO by terahertz time-domain spectroscopy (THz-TDS) from 0.2 THz − 3 THz. After annealing, strong absorption peaks appear in k(ω), with peak positions shifting to higher frequencies with increasing temperature.

Our investigated samples are single crystals of (100) LAO: a 10×10×1 mm³ piece from CrysTec GmbH (Berlin, Germany), and a 10×10×0.5 mm³ piece from SWI (Hsinchu, Taiwan). Since both samples give the similar results, we only show data from the CrysTec sample. The dielectric response of LAO was measured by a commercial THz-TDS system (TeraView Spectra 3000). .........."

For TeraView's full range of products see http://www.teraview.com/products/index.html 

Dielectric Spectroscopy for Soft Matter Research (Terahertz research in Spain part 1)

Written by Prof. Dr. Angel Alegria  who is the head of the Material Physics Department at University of the Basque Country, Spain in the European Soft Matter Infrastructure Newsletter

For more information click here (http://www.emat.ua.ac.be/ESMI_Newsletter.pdf)


The Dielectric Spectroscopy Laboratory (DSL) is one of the laboratories of the Material Physics Center (MPC), a joint research center set up in 2001 by the Univer- sity of the Basque Country (UPV/EHU) in collaboration with the Spanish National Research Council (CSIC).

Since then, the Polymers and Soft Matter Group (PSMG) laboratory has been further developed and upgraded in order to improve the quality of the different experimental set-ups and to facilitate the operation of the infrastructure by external users. The operative set-ups of DSL offer the unique possibility of performing high precision dielectric relaxation experiments over a huge range of frequencies (from 10^-5 to 3-10^10Hz, i.e. nearly 16 orders of magnitude).

Depending on the frequency range involved, these experiments can be carried out in different sample environments where temperature can be varied over a wide range (from 20 - 600 K) and pressure can be increased up to 300 MPa. Furthermore, the existing equipment allows experiments to be performed with simultaneous access to electric/dielectric and mechanical/rheological frequency dependent properties. The current range of instruments, listed in order offrequency range, are:

- Time-Domain Dielectric Spectrometer

- Broad-Band Dielectric Spectrometer

- High-Frequency Dielectric Spectrometer

- Micro-Wave Spectrometer

- Tera-Hertz Spectrometer

Technical details of the various instruments can be found on the ESMI website and at:

www.sc.ehu.es/sqwpolim/PSMG/dielab.html 

Most of the equipment uses widely-avai- lable software, and the temperature control systems are such that different set-ups do not generally involve specific training for each piece of equipment. In addition to the dielect- ric spectroscopy instruments, the infra- structure also provides several facilities for sample preparation and standard sample characterization (such as DSC, TGA, PVT, etc.). Details can be found at:

www.sc.ehu.es/sqwpolim/PSMG/infr.html

The scientists in charge of the various instruments are: Dr. Silvina Cerveny (Micro-Wave and Tera- Hertz spectrometers), Dr. Gustavo Schwartz (non-conventional sample environment), Dr. Silvia Arrese-Igor (Time-Domain and standard Dielectric Spectrometers).

For more information about  the Spectra 3000 terahertz spectrometer click here

or visit http://www.teraview.com/products/terahertz-pulsed-spectra-3000/index.html

Promieniowanie terahercowe w naukach farmaceutycznych

A review paper in Polish about the applications of terahertz in the pharmaceutical industry. 

Bożena Karolewicz1, Edward F. Pliński2, Agata Górniak3, Artur Owczarek1, Karol Nartowski1, Janusz Pluta1, Bogusław Fuglewicz3, Stanisława Plińska3, Przemysław P. Jarząb2, Kacper Nowak2, M. J. Walczakowski2, Ł. Augustyn2

1Akademia Medyczna, Katedra Technologii Postaci Leku, ul. Szewska 38, 50-139 Wrocław 2Politechnika Wrocławska, Wydział Elektroniki, Instytut Telekomunikacji, Teleinformatyki i Akustyki, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław 3Akademia Medyczna, Katedra i Zakład Chemii Nieorganicznej, ul. Szewska 38, 50-139 Wrocław

Adres do korespondencji: Bożena Karolewicz, Katedra Technologii Postaci Leku, Wydział Farmaceutyczny z Oddziałem Analityki Medycznej, Akademia Medyczna im. Piastów Śląskich, ul. Szewska 38, 50-139 Wrocław, e-mail: bozkar@ktpl.am.wroc.pl

Zaawansowane techniki pomiarowe, umożli- wiające potwierdzanie tożsamości substancji czynnej i substancji pomocniczych znajdujących się w gotowym produkcie stają się podstawowymi me- todami analizy leku. Promieniowanie terahercowe (w zakresie od 2 cm-1 do 130 cm-1) może być wy- korzystane do identyfikacji substancji w procesie ich produkcji, co wiąże się bezpośrednio z kontrolą jakości i bezpieczeństwem wytwarzania. Technika spektroskopii terahercowej umożliwia prowadze- nie analizy jakościowej i ilościowej substancji lecz- niczych i pomocniczych w postaci leku, w szcze- gólności jest wykorzystywana do identyfikacji form polimorficznych i pseudopolimorficznych substan- cji oraz pozyskiwania informacji dotyczących ho- mogenności otoczek wytworzonych tabletek [1]. Jest to nowoczesna, nieinwazyjna i niedestrukcyjna metoda analizy produktów leczniczych umożliwia- jąca jednoczesne pozyskiwanie obrazu danej próbki (informacje przestrzenne o rozmieszczeniu poszcze- gólnych składników) i rejestrację widm spektral- nych związków chemicznych wchodzących w skład danego obiektu (informacje o strukturze chemicz- nej związków) [2, 3]. Metoda ta pozwala również na określenie rozmieszczenia poszczególnych skład- ników w gotowej formie leku, tj. proszki, tablet- ki, kapsułki czy granulaty oraz na monitorowanie zmian we właściwościach fizycznych API, tj. prze- miany postaci polimorficznych następujące w pro- cesie wytwarzania lub przechowywania gotowego preparatu, czy interakcje pomiędzy substancjami pomocniczymi, tj. polimery i API w mieszaninach fizycznych [4].

for more information click here (http://www.aprehabilitacja.pl/pub/Promieniowanie_THz.pdf)

For help with your pharmaceutical problems also seehttp://www.teraview.com/services/applications-support/index.html

for more information about  the Spectra 3000 spectrometer click here

(http://www.teraview.com/products/terahertz-pulsed-spectra-3000/index.html)

In case you missed the 2012 Lasers & Photonics Marketplace Seminar - Laser Focus World

In case you missed the 2012 Lasers & Photonics Marketplace Seminar - Laser Focus World

Terahertz localized surface plasmon resonance of periodic silicon microring arrays

J. Grant, X. Shi, J. Alton and D. R. S. Cumming


J. Appl. Phys. 109, 054903 (2011); http://dx.doi.org/10.1063/1.3553441 


Abstract

We demonstrate the absorption characteristics of silicon microring resonators at terahertz frequencies. Simulation and experimental data show a dipolar localized surface plasmon resonance (DLSPR) absorption peak. We demonstrate that the frequency position and magnitude of the DLSPR peak may be tuned by varying the geometry and thickness of the microring or by modification of the silicon impurity concentration. Finite difference time domain simulations reveal that there is a strong enhancement of the electric field at the resonant frequency. The absorption properties of our resonator are described in terms of effective optical constants and reveal that the silicon microring is an electric resonator. Surface plasmon resonators are efficient terahertz absorbers and have potential applications in security imaging, biological analysis, spectroscopy and non destructive testing.

These measurements where done using TeraView's TPS spectra 3000 THz spectrometer

For TeraView's range of products see http://www.teraview.com/products/index.html

UK imaging company finds niche in dayton's high-tech biz sector

From hi Velocity 


One year after TeraView opened its first U.S. office, the UK-based imaging company is finding its niche within Dayton's vibrant, high-tech business sector. Dayton was the logical locale for TeraView's U.S. office because the region is a center for aerospace engineering and the development of advanced sensor technologies.

TeraView’s Dayton office is housed within the the Institute for the Development and Commercialization of Advanced Sensor Technology (IDCAST), a facility established by the University of Dayton with a $28 million Third Frontier grant in 2008. The company develops technologies using Terahertz light for imaging and spectroscopy that have pharmaceutical, biomedical and military applications.
 
“We have had a long relationship with Dayton and with a number of the excellent Universities in the state,” says TeraView spokesperson Alessia Portieri. “There is a now a strong Terahertz network in the area. This was one of the key reasons why we selected Dayton to create our base.”
 
Over the past year, Teraview has conducted two Terahertz techonology training sessions through IDCAST, a facility that has over 30 companies and eight universities as its partners and is considered one of the most prominent advanced sensor research and development centers in the U.S.

“These have been well attended by people from across the U.S. and helped to raise the profile of Terahertz, Teraview and the capabilities of Ohio,” says Portieri. TeraView’s Dayton location supports Terahertz technology projects in surrounding states, including an ongoing project in Indiana.
 
TeraView has just raised $5.5 million of new investment, and more training events are in the works, including one aimed at the pharmaceutical industry. “We’ve just moved additional equipment into the facility and are starting to offer contract analytical services,” says Portieri. The company hopes to eventually see U.S. interest for TeraView applications rise to the level of its European demand.
 
As the Ohio-based operation shows progress in the US market, TeraView plans to add more jobs in the Dayton facility. Meanwhile, the company plans on subcontracting existing work to IDCAST teams. 


see http://www.hivelocitymedia.com/innovationnews/?page=all&city=5ae2e843-4535-430d-aabc-2cfdcadebcdf  

For TeraView's range of products see http://www.teraview.com/products/index.html

For more information information click here 

2-nd International Conference - Terahertz and Microwave radiation: Generation, Detection and Applications

The TERA-2012 conference is devoted to the fundamental and applied issues of the generation and detection of terahertz and microwave radiation as well as their interaction with matter. The Conference will be held in Lomonosov Moscow State University in the form of plenary (40 min talks), invited (30 min talks), oral (20 min talks), and poster presentations.

All contributions will be reviewed for technical merit and content by the International Program Committee on the basis of the abstracts submitted by the authors. Main criteria for paper acceptance are originality, significance of presented results, quality and completeness of the abstracts. The accepted papers will be assigned to either oral or poster presentation at the discretion of the International Program Committee.

All contributions should be presented in English that is the official language of the Conference.

Topics and sections

• Modern methods of generation of terahertz and microwave radiation
• Detection of terahertz and microwave radiation. Metrology in terahertz frequency range.
• Study of materials (including nano- and metamaterials) with the help of terahertz and microwave radiation. Time-domain and continuous-wave spectroscopy.
• Interaction of high power terahertz and microwave radiation with matter. Application of terahertz radiation for the research and control of ultrafast process in physics, chemistry and biology.
• Terahertz and microwave imaging: radiovision, tomography and near-field microscopy.
• Systems of security and non-destructive control using terahertz and microwave radiation. Communication in terahertz frequency range.
• Medical and biological applications of terahertz wave radiation.

for more information see http://tera2012.phys.msu.ru/home

The potential of terahertz imaging for cancer diagnosis: A review of investigations to date

 Yu C, Fan S, Sun Y, Pickwell-Macpherson E. The potential of terahertz imaging for cancer diagnosis: A review of investigations to date. Quant Imaging Med Surg 2012;2:33-45. DOI: 10.3978/ j.issn.2223-4292.2012.01.04


Abstract


The terahertz region lies between the microwave and infrared regions of the electromagnetic spectrum such that it is strongly attenuated by water and very sensitive to water content. Terahertz radiation has very low photon energy and thus it does not pose any ionization hazard for biological tissues. Because of these characteristic properties, there has been an increasing interest in terahertz imaging and spectroscopy for biological applications within the last few years and more and more terahertz spectra are being reported, including spectroscopic studies of cancer. The presence of cancer often causes increased blood supply to affected tissues and a local increase in tissue water content may be observed: this acts as a natural contrast mechanism for terahertz imaging of cancer. Furthermore the structural changes that occur in affected tissues have also been shown to contribute to terahertz image contrast. This paper introduces terahertz technology and provides a short review of recent advances in terahertz imaging and spectroscopy techniques. In particular investigations relating to the potential of terahertz imaging and spectroscopy for cancer diagnosis will be highlighted.


for more information click here (http://www.amepc.org/qims/article/view/106/117)

For TeraView's range of products see http://www.teraview.com/products/index.html

For more information information click here 

Terahertz pulsed imaging study to assess remineralization of artificial caries lesions (J. Biomed. Opt. 16, 026001)

David Churchley and Richard J. M. Lynch

GlaxoSmithKline, St Georges Avenue, Weybridge, Surrey, KT13 0DE, United Kingdom

Frank Lippert and Jennifer Susan O’Bryan Eder

Indiana University School of Dentistry, Oral Heath Research Institute, 415 Lansing Street, Indianapolis, Indiana 46202

Jesse Alton

TeraView Ltd, Platinum Building, St John's Innovation Park, Cambridge CB4 0WS, United Kingdom

Carlos Gonzalez-Cabezas

University of Michigan, School of Dentistry, 1011 N. University B305, Ann Arbor, Michigan 48109–1078

Abstract

We compare terahertz–pulsed imaging (TPI) with transverse microradiography (TMR) and microindentation to measure remineralization of artificial caries lesions. Lesions are formed in bovine enamel using a solution of 0.1 M lactic acid/0.2% Carbopol C907 and 50% saturated with hydroxyapatite adjusted to pH 5.0. The 20-day experimental protocol consists of four 1 min treatment periods with dentifrices containing 10, 675, 1385, and 2700 ppm fluoride, a 4-h∕day acid challenge, and, for the remaining time, specimens are stored in a 50:50 pooled human∕artificial saliva mixture. Each specimen is imaged at the focal point of the terahertz beam (data-point spacing = 50 μm).........

For more information see http://dx.doi.org/10.1117/1.3540277

For TeraView's range of products see http://www.teraview.com/products/index.html

For more information click here 

Business Weekly - Killer 50 companies

TeraView Limited is listed as one of  Business Weekly's 50 hottest, disruptive technology companies in Cambridge and the East of England.


For more information click here
(http://www.businessweekly.co.uk/the-killer50/killer50-profiles?start=32)


For more information about TeraView and its products visit http://www.teraview.com/

Failure Analysis of Integrated Circuits using THz EOTPR

TeraView will be exhibiting at the 19th IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits - IPFA 2012.  


Dates: 2nd - 6th July 2012


Location: Marina Bay Sands®, Singapore

This conference is organized by the IEEE Reliability/CPMT/ED Singapore Chapter. The Symposium is technically co-sponsored by the IEEE Electron Device Society and IEEE Reliability Society. Also, IPFA will be celebrating its 25th year in 2012. 

For more information about the conference please click here  
(http://ewh.ieee.org/reg/10/ipfa/index.php/home )


For information about TeraView's products please visit
http://www.teraview.com/products/thz-reflectometry/index.html

Come and visit us!

To organise a meeting either at the conference or if you would like to learn more about how our products can help solve your problems please e-mail Martin Igarashi (martin.igarashi@teraview.com)

CALL FOR PAPERS - IEEE Sensors Journal

IEEE Sensors Journal

Special issue on

THz Sensing: Materials, Devices and Systems

The THz frequencies encompassing 100 GHz to 10 THz offer many attractive properties for applications ranging from the characterisation of novel materials, hazard detection, high speed data communications, to radio astronomy. Recent technological advances have significantly increased the availability of photonic and electronic-based sources, as well as detectors operating at THz frequencies leading to the generation of a significant volume of scientific research. The increased availability of a wide range of sensor system components such as sources, detectors, mixers, waveguides, materials, etc is a critical in the development of this spectral range to the sophistication of the neighbouring microwave and infrared domains.

It is intended that this Special Issue of the IEEE Sensors Journal will show the state-of-the-art in THz expertise and technology dedicated to sensing problems presently accomplished by THz radiation and its potential to overcome challenges of new measurement applications. Original research contributions, tutorials and review papers are sought in THz-related areas including (but not limited to):

• Materials
• Devices
• Systems
• Applications

Solicited and invited papers shall undergo the standard IEEE Sensors Journal peer review proc­ess. All manuscripts must be submitted on-line, via the IEEE Manuscript CentralTM, see http://sensors-ieee.manuscriptcentral.com. When submitting, please indicate in the “Manuscript Type” roll down menu, and also by e-mail to Ms. Alison Larkin, a.larkin@ieee.org, that the paper is intended for the “THz Sensing…” Special Issue. Authors are particularly encouraged to suggest names of potential reviewers for their manu­scripts in the space provided for these recommen­dations in Manuscript Central. For manuscript prepara­tion and submission, please follow the guidelines in the Information for Authors at the IEEE Sensors Journal web page, http://www.ieee.org/sensors

Deadlines:

Manuscript Submission:                                       June 1, 2012

·          Notification of Acceptance :                                 September 1, 2012

·          Final Manuscript published in IEEExplore:        October 1, 2012

·          Tentative date of paper issue:                            January 2013

Guest Editors:

Michael Shur

Electrical, Computer, & Systems Engineering

Rensselaer Polytechnic Institute

shurm@rpi.edu

Derek Abbott

Electrical and Electronic Engineering

University of Adelaide dabbott@eleceng.adelaide.edu.au

Krikor B Ozanyan

Electrical Engineering and Electronics

The University of Manchester

K.Ozanyan@Manchester.ac.UK

Francis Hindle

Laboratoire de Physico-Chimie de l'Atmosphère

Université du Littoral

Francis.Hindle@univ-littoral.fr

TeraView to present at the 37th Annual Focus Conference on paints

THE DETROIT SOCIETY FOR COATINGS TECHNOLOGY

37^th Annual Focus Conference

THURSDAY, MAY 3, 2012

At the MSU MANAGEMENT EDUCATION CENTER, TROY, MI

Terahertz Light for Measuring Coating Thickness and Paint Defects

by 

David Reece

Abstract

Terahertz light lies between infrared and microwaves. TeraView has been developing terahertz technology and applications for over 10 years in several industries. Rapid, non-destructive and non-contact, low power terahertz light pulses can accurately measure individual layer thickness of a multiple layer paint coating and can be used to rapidly scan large areas with multiple readings. This can enable 100% quality inspection of multiple panels and also be used as a diagnostic tool for defects and process development. This talk will discuss advances in the use of terahertz light from the research arena towards real world applications in industry. Demonstrating work initially developed for measuring pharmaceutical tablet coatings, applications within automotive and industrial paint and coating applications will be discussed.

for more information click here (http://www.dsct.org/speakers.html)

To arrange a meeting with the speaker please e-mail (david.reece@teraview.com)


Also see http://www.teraview.com/applications/nondestructive-testing/paint.html

Application of Terahertz Pulsed Imaging to Assess the Film Coating Characteristics of Sustained-Release Coated Pellets

University of Otago, TeraView, and Université Lille Nord de France present at the 8th World Meeting on Pharmaceutics, Biopharmaceutics and Pharmaceutical Technology

Application of Terahertz Pulsed Imaging to Assess the Film Coating Characteristics of Sustained-Release Coated Pellets

Miriam Haaser, Youness Karrout, Carine Velghe, Yvonne Cuppok, Keith C. Gordon, Michael Pepper, Jürgen Siepmann, Clare J. Strachan, Philip F. Taday, Thomas Rades

School of Pharmacy, Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, Dunedin, New Zealand

TeraView Limited, Cambridge, United Kingdom

Cavendish Laboratory, University of Cambridge, Cambridge , United Kingdom

College of Pharmacy, Université Lille Nord de France, Lille, France

Department of Electronic Engineering, University College London, London, United Kingdom

Abstract

Terahertz pulsed imaging (TPI) was employed for the first time to explore its suitability for detecting differences in the coating thickness and internal characteristics of standard size pellets (1 mm in diameter).  Furthermore, the effect of coating characteristics on the subsequent drug release behaviour of the pellets was investigated.

For more information click here

For help with your pharmaceutical problems also see

http://www.teraview.com/services/applications-support/index.html

Requests for a review paper

A number of people have asked for a good review paper on the application of terahertz in the pharmaceutical industry.  Just to remind you of the paper by Dr Y.C. Shen from Liverpool University

Terahertz pulsed spectroscopy and imaging for pharmaceutical applications: A review

International Journal of Pharmaceutics

Volume 417, Issues 1–2 

Pages 48–60

Yao-Chun Shen

For help with your pharmaceutical problems also see
http://www.teraview.com/services/applications-support/index.html