Pub Date : 2015-03-07DOI: 10.1109/ISPTS.2015.7220104
T. Grigorie, P. Negrea, Florentina Cirstea
The paper presents theoretical and numerical study of a MEMS vibration gyro based Coriolis effect. Two configurations of the gyro are modeled and simulated here: 1) with assumed control on the excitation axis (a simplified configuration used to validate the second one); and 2) gyro controlled on the excitation axis. Shown are: general dynamic equations of the gyrometer, mathematical models ant the resulted block diagrams for the two configurations, the control strategy for the second configuration, software implementations of the models and numerical simulations results.
{"title":"Modelling and simulation of a miniaturized gyrometer","authors":"T. Grigorie, P. Negrea, Florentina Cirstea","doi":"10.1109/ISPTS.2015.7220104","DOIUrl":"https://doi.org/10.1109/ISPTS.2015.7220104","url":null,"abstract":"The paper presents theoretical and numerical study of a MEMS vibration gyro based Coriolis effect. Two configurations of the gyro are modeled and simulated here: 1) with assumed control on the excitation axis (a simplified configuration used to validate the second one); and 2) gyro controlled on the excitation axis. Shown are: general dynamic equations of the gyrometer, mathematical models ant the resulted block diagrams for the two configurations, the control strategy for the second configuration, software implementations of the models and numerical simulations results.","PeriodicalId":6520,"journal":{"name":"2015 2nd International Symposium on Physics and Technology of Sensors (ISPTS)","volume":"20 4","pages":"162-168"},"PeriodicalIF":0.0,"publicationDate":"2015-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91490517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-03-07DOI: 10.1109/ISPTS.2015.7220117
Pratanu Nag, P. Devi
There is a growing interest in developing efficient and economically viable hydrogen (H2) sensors for the swift detection of leakage of H2 in areas where hydrogen is used. In the present study we have prepared palladium catalysed antimony doped tin dioxide by sonochemical process, as a H2 gas sensing material for 1000 ppm to 8% by volume H2 gas concentration. The electrical characteristics of the sensors before and after the H2 exposure show significant changes at different temperatures. The response even shows more than 86% at 300 °C towards 1000 ppm H2 gas in a selective manner.
{"title":"Hydrogen sensing properties of antimony doped tin dioxide based taguchi type gas sensor: Effect of palladium","authors":"Pratanu Nag, P. Devi","doi":"10.1109/ISPTS.2015.7220117","DOIUrl":"https://doi.org/10.1109/ISPTS.2015.7220117","url":null,"abstract":"There is a growing interest in developing efficient and economically viable hydrogen (H<sub>2</sub>) sensors for the swift detection of leakage of H<sub>2</sub> in areas where hydrogen is used. In the present study we have prepared palladium catalysed antimony doped tin dioxide by sonochemical process, as a H<sub>2</sub> gas sensing material for 1000 ppm to 8% by volume H<sub>2</sub> gas concentration. The electrical characteristics of the sensors before and after the H<sub>2</sub> exposure show significant changes at different temperatures. The response even shows more than 86% at 300 °C towards 1000 ppm H<sub>2</sub> gas in a selective manner.","PeriodicalId":6520,"journal":{"name":"2015 2nd International Symposium on Physics and Technology of Sensors (ISPTS)","volume":"77 1","pages":"224-229"},"PeriodicalIF":0.0,"publicationDate":"2015-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91541615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-03-07DOI: 10.1109/ISPTS.2015.7220131
Mayur Devrukhakar, Mangesh Dayaphule, Varsha Chaware, V. Giramkar, S. Joseph, G. Phatak
LTCC is a known suitable platform for microfluidic systems. We have developed actuation-less non-return valve for gases and liquids, which is based upon the inlet and reverse pressure. This work compares three different designs of such valves. In these designs, top lid and bottom cavity layer together forms micro fluidic channel, through which fluid or gas can flow. The pressure based movable ceramic part and the matching cavity at the inlet plays an important role in the valve designs. The designs are such that the liquid or gas flows from inlet to outlet without any difficulty. However, if the liquid or gas flows in reverse direction (i.e. from outlet to inlet) the movable part blocks the path at the cavity and opposes the liquid or gas flow through the channel. Two designs are based upon vertical motion of the movable ceramic part and has a `O' ring to rest to movable part at the inlet side. One of these designs usesZirconia (ZrO2) ball (design 2) while another has square shape (design 3) as the movable parts. Yet another design (design 1) is based upon sliding motion and teflon coating for lubrication. The initial testing using pressurised air (up to 6 bar) indicated that the reverse direction blockade is the best for design 2, which has shown leak rate of 3 ml min-1 at 6bar pressure. This is followed by design 3 and by design 1, which have shown leak rates of 30 ml min-1 and 100ml min-1 respectively.
LTCC是一个已知的适合微流体系统的平台。我们已经开发了用于气体和液体的无驱动止回阀，该止回阀基于进口和反向压力。这项工作比较了三种不同设计的这种阀门。在这些设计中，上盖和下腔层共同形成微流体通道，流体或气体可以通过该通道流动。在阀门设计中，基于压力的可动陶瓷部件和进口处的匹配腔体起着重要的作用。这种设计使液体或气体从进口流向出口没有任何困难。然而，如果液体或气体以相反的方向流动(即从出口流向进口)，则可动部件在空腔处阻塞路径并与液体或气体通过通道的流动相反。两种设计基于可移动陶瓷部件的垂直运动，并且在进口侧具有一个“O”形环以静止在可移动部件上。其中一种设计使用氧化锆(ZrO2)球(设计2)，而另一种设计采用方形(设计3)作为可移动部件。另一种设计(设计1)是基于滑动运动和聚四氟乙烯涂层润滑。使用加压空气(高达6bar)的初步测试表明，反向封锁是设计2的最佳选择，在6bar压力下，泄漏率为3 ml min-1。其次是设计3和设计1，它们分别显示泄漏率为30 ml min-1和100ml min-1。
{"title":"Non-return microvalve using low temperature co-fired ceramic (LTCC)","authors":"Mayur Devrukhakar, Mangesh Dayaphule, Varsha Chaware, V. Giramkar, S. Joseph, G. Phatak","doi":"10.1109/ISPTS.2015.7220131","DOIUrl":"https://doi.org/10.1109/ISPTS.2015.7220131","url":null,"abstract":"LTCC is a known suitable platform for microfluidic systems. We have developed actuation-less non-return valve for gases and liquids, which is based upon the inlet and reverse pressure. This work compares three different designs of such valves. In these designs, top lid and bottom cavity layer together forms micro fluidic channel, through which fluid or gas can flow. The pressure based movable ceramic part and the matching cavity at the inlet plays an important role in the valve designs. The designs are such that the liquid or gas flows from inlet to outlet without any difficulty. However, if the liquid or gas flows in reverse direction (i.e. from outlet to inlet) the movable part blocks the path at the cavity and opposes the liquid or gas flow through the channel. Two designs are based upon vertical motion of the movable ceramic part and has a `O' ring to rest to movable part at the inlet side. One of these designs usesZirconia (ZrO2) ball (design 2) while another has square shape (design 3) as the movable parts. Yet another design (design 1) is based upon sliding motion and teflon coating for lubrication. The initial testing using pressurised air (up to 6 bar) indicated that the reverse direction blockade is the best for design 2, which has shown leak rate of 3 ml min-1 at 6bar pressure. This is followed by design 3 and by design 1, which have shown leak rates of 30 ml min-1 and 100ml min-1 respectively.","PeriodicalId":6520,"journal":{"name":"2015 2nd International Symposium on Physics and Technology of Sensors (ISPTS)","volume":"5 1","pages":"289-292"},"PeriodicalIF":0.0,"publicationDate":"2015-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82297503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-03-07DOI: 10.1109/ISPTS.2015.7220082
Sudha Bendapudi, G. K. Kashyap, M. G. Lithin, M. Subhajit, B. Krishnamprasad, T. H. Shashikala
Star Sensor, also known as star-tracker, is a high-accuracy 3-axis attitude sensor used onboard spacecrafts. It processes stars from a sky image captured using an area imaging detector (generally 1k × 1k pixels Charge Coupled Device) to generate attitude information. Its accuracy about the boresight is poorer than about the cross-axes. This is improved by using two sensor heads with staggered Fields-Of-View (FOVs) and three to avoid break during occultation of any head. All the sensor heads have identical processing operations. So, the Processing Unit (PU) is made common. This minimizes the system electronics, power consumption and also thermal dissipation on each CH, allowing more efficient cooling of CCD and improving sensor performance. The resulting multiple Camera Heads (CHs) are operated remotely by the common PU. Thus, a programmable Video Processor (VP) is designed for the CH as an efficient data acquisition co-processor to the PU. The VP works in parallel freeing PU for attitude computation from the data acquired from multiple CHs. VP acquires CCD images and pre-processes them to reduce data size, speeding up PU processing. It is programmable for different modes of operation based on full-frame star-search or Region-of-Interest (ROI) readout, thereby providing flexibility, while maintaining rigidity in implementation as required by CCD. Communication of the VP with the PU is configured via low-power high-speed SpaceWire link. The VP is implemented in a low-power FPGA. All instruction and data storage is on-chip.
{"title":"Design of video processor for multi-head star sensor","authors":"Sudha Bendapudi, G. K. Kashyap, M. G. Lithin, M. Subhajit, B. Krishnamprasad, T. H. Shashikala","doi":"10.1109/ISPTS.2015.7220082","DOIUrl":"https://doi.org/10.1109/ISPTS.2015.7220082","url":null,"abstract":"Star Sensor, also known as star-tracker, is a high-accuracy 3-axis attitude sensor used onboard spacecrafts. It processes stars from a sky image captured using an area imaging detector (generally 1k × 1k pixels Charge Coupled Device) to generate attitude information. Its accuracy about the boresight is poorer than about the cross-axes. This is improved by using two sensor heads with staggered Fields-Of-View (FOVs) and three to avoid break during occultation of any head. All the sensor heads have identical processing operations. So, the Processing Unit (PU) is made common. This minimizes the system electronics, power consumption and also thermal dissipation on each CH, allowing more efficient cooling of CCD and improving sensor performance. The resulting multiple Camera Heads (CHs) are operated remotely by the common PU. Thus, a programmable Video Processor (VP) is designed for the CH as an efficient data acquisition co-processor to the PU. The VP works in parallel freeing PU for attitude computation from the data acquired from multiple CHs. VP acquires CCD images and pre-processes them to reduce data size, speeding up PU processing. It is programmable for different modes of operation based on full-frame star-search or Region-of-Interest (ROI) readout, thereby providing flexibility, while maintaining rigidity in implementation as required by CCD. Communication of the VP with the PU is configured via low-power high-speed SpaceWire link. The VP is implemented in a low-power FPGA. All instruction and data storage is on-chip.","PeriodicalId":6520,"journal":{"name":"2015 2nd International Symposium on Physics and Technology of Sensors (ISPTS)","volume":"98 1","pages":"59-62"},"PeriodicalIF":0.0,"publicationDate":"2015-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79482109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-03-07DOI: 10.1109/ISPTS.2015.7220113
Apoorva Garje, Y. Adhav, D. Bodas
In this paper, we present two-dimensional modeling and simulation of blood vessel using COMSOL Multiphysics. The rationale behind this study is that mathematical modeling and numerical simulation can lead to better understanding of the phenomena involved in vascular diseases. This study assumes that the fluid is laminar, non-Newtonian, viscous and compressible and the arterial wall is elastic. Parameters of blood vessel were assigned to the wall and parameters for fat deposits to the blockages. Blood is an example of a non-Newtonian fluid applied to the model in the present simulations. Structural deformation and fluid dynamics are determined simultaneously.
{"title":"Design and simulation of blocked blood vessel for early detection of heart diseases","authors":"Apoorva Garje, Y. Adhav, D. Bodas","doi":"10.1109/ISPTS.2015.7220113","DOIUrl":"https://doi.org/10.1109/ISPTS.2015.7220113","url":null,"abstract":"In this paper, we present two-dimensional modeling and simulation of blood vessel using COMSOL Multiphysics. The rationale behind this study is that mathematical modeling and numerical simulation can lead to better understanding of the phenomena involved in vascular diseases. This study assumes that the fluid is laminar, non-Newtonian, viscous and compressible and the arterial wall is elastic. Parameters of blood vessel were assigned to the wall and parameters for fat deposits to the blockages. Blood is an example of a non-Newtonian fluid applied to the model in the present simulations. Structural deformation and fluid dynamics are determined simultaneously.","PeriodicalId":6520,"journal":{"name":"2015 2nd International Symposium on Physics and Technology of Sensors (ISPTS)","volume":"1 1","pages":"204-208"},"PeriodicalIF":0.0,"publicationDate":"2015-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72642226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-03-07DOI: 10.1109/ISPTS.2015.7220089
Amit Pawbake, V. Waman, R. Waykar, A. Mayabadi, R. Kulkarni, H. Pathan, S. Jadkar
Hydrogenated nanocrystalline silicon carbide (nc-SiC:H) films were prepared by hot wire chemical vapor deposition (HW-CVD) method using ethane (C2H6) as a carbon precursor. The influence of deposition pressure on structural and optical properties was investigated. The formation of nc-SiC:H films was confirmed by low angle x-ray diffraction (XRD), Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy analysis. An inverse relation between deposition pressure and deposition rate was observed. Optical band gap values, ETauc and E04 increases with increase in deposition pressure. In fact, optical band gap values estimated from E04 method was found higher than the ETauc values calculated from Tauc's plot. Finally, at optimized deposition pressure (450 mTorr), a photo detector having configuration glass/nc-SiC:H/Al have been fabricated and its photo response was studied. Further study is required to improve the quality of nc-SiC:H films to make use in photo detectors.
{"title":"Synthesis of nanocrystalline silicon carbide thin films by HW-CVD using ethane carbon precursor for photo detector application","authors":"Amit Pawbake, V. Waman, R. Waykar, A. Mayabadi, R. Kulkarni, H. Pathan, S. Jadkar","doi":"10.1109/ISPTS.2015.7220089","DOIUrl":"https://doi.org/10.1109/ISPTS.2015.7220089","url":null,"abstract":"Hydrogenated nanocrystalline silicon carbide (nc-SiC:H) films were prepared by hot wire chemical vapor deposition (HW-CVD) method using ethane (C2H6) as a carbon precursor. The influence of deposition pressure on structural and optical properties was investigated. The formation of nc-SiC:H films was confirmed by low angle x-ray diffraction (XRD), Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy analysis. An inverse relation between deposition pressure and deposition rate was observed. Optical band gap values, ETauc and E04 increases with increase in deposition pressure. In fact, optical band gap values estimated from E04 method was found higher than the ETauc values calculated from Tauc's plot. Finally, at optimized deposition pressure (450 mTorr), a photo detector having configuration glass/nc-SiC:H/Al have been fabricated and its photo response was studied. Further study is required to improve the quality of nc-SiC:H films to make use in photo detectors.","PeriodicalId":6520,"journal":{"name":"2015 2nd International Symposium on Physics and Technology of Sensors (ISPTS)","volume":"33 1","pages":"88-93"},"PeriodicalIF":0.0,"publicationDate":"2015-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91231155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-03-07DOI: 10.1109/ISPTS.2015.7220160
S. .. Krupanidhi
Long-wavelength infrared (LWIR) detectors are important in many different applications such as space surveillance systems, low-background infrared seeker-tracker systems, remote environmental monitoring, remote analysis of gases in outer space, and remote temperature measurement. One primary concern with producing LWIR detectors is that they must be made with a material having an energy band gap small enough to allow electrons to be excited from the valence band to the conduction band by the infrared radiation. However, the lowest band gap of the III-V material family is InSb (Eg= 0.174 eV @ 300 K), which corresponds to a wavelength of about 7.1 μm. This makes it difficult to fabricate a long-wavelength (8-14 μm) detector from a bulk III-V material. One way to approach is to make use of quantum wells (QWs) grown in the III-V material family. A QW is made when a thin layer of small band gap material is sandwiched between materials that have a higher band gap. This higher band gap material is called the barrier, where as the lower band gap material is called the well. If the well is thin enough and deep enough, then instead of a continuum of allowed states like those in the conduction band of a bulk semiconductor, a few discrete states are formed in the well. The number of discrete states that are formed depend on the physical and material properties of the well and barrier. Present talk deals with the development of Quantum wells and Dots of GaAs for efficient IR detection.
长波红外(LWIR)探测器在许多不同的应用中都很重要，例如空间监视系统、低背景红外导引头跟踪系统、远程环境监测、外层空间气体远程分析和远程温度测量。制造低波长红外探测器的一个主要问题是，制造低波长红外探测器的材料必须具有足够小的能带间隙，以允许电子被红外辐射从价带激发到导带。而III-V材料族的最低带隙为InSb (Eg= 0.174 eV @ 300 K)，对应的波长约为7.1 μm。这使得用大块III-V材料制造长波长(8-14 μm)探测器变得困难。一种方法是利用在III-V材料族中生长的量子阱(qw)。当一层薄的小带隙材料夹在具有较高带隙的材料之间时，就形成了量子阱。这种高带隙的材料称为势垒，而低带隙的材料称为阱。如果阱足够薄、足够深，那么阱中就会形成一些离散态，而不是像体半导体的导带中那样连续的允许态。所形成的离散态的数量取决于井和势垒的物理和材料性质。本文讨论了用于高效红外探测的砷化镓量子阱和量子点的发展。
{"title":"PT04. III-V Compound semiconductors based quantum structures for IR detection","authors":"S. .. Krupanidhi","doi":"10.1109/ISPTS.2015.7220160","DOIUrl":"https://doi.org/10.1109/ISPTS.2015.7220160","url":null,"abstract":"Long-wavelength infrared (LWIR) detectors are important in many different applications such as space surveillance systems, low-background infrared seeker-tracker systems, remote environmental monitoring, remote analysis of gases in outer space, and remote temperature measurement. One primary concern with producing LWIR detectors is that they must be made with a material having an energy band gap small enough to allow electrons to be excited from the valence band to the conduction band by the infrared radiation. However, the lowest band gap of the III-V material family is InSb (Eg= 0.174 eV @ 300 K), which corresponds to a wavelength of about 7.1 μm. This makes it difficult to fabricate a long-wavelength (8-14 μm) detector from a bulk III-V material. One way to approach is to make use of quantum wells (QWs) grown in the III-V material family. A QW is made when a thin layer of small band gap material is sandwiched between materials that have a higher band gap. This higher band gap material is called the barrier, where as the lower band gap material is called the well. If the well is thin enough and deep enough, then instead of a continuum of allowed states like those in the conduction band of a bulk semiconductor, a few discrete states are formed in the well. The number of discrete states that are formed depend on the physical and material properties of the well and barrier. Present talk deals with the development of Quantum wells and Dots of GaAs for efficient IR detection.","PeriodicalId":6520,"journal":{"name":"2015 2nd International Symposium on Physics and Technology of Sensors (ISPTS)","volume":"27 1","pages":"iv-iv"},"PeriodicalIF":0.0,"publicationDate":"2015-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83053058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-03-07DOI: 10.1109/ISPTS.2015.7220136
L. S. Vaidhyanathan, D. K. Baisnab, R. Baskaran, M. Janawadkar
The HTS SQUID sensors coupled to an on-chip integrated planar gradiometric pick-up loop were fabricated using highly reliable advanced micro-fabrication techniques such as deposition of superconducting thin films by Pulsed Laser Deposition (PLD), UV photolithography and RF ion beam etching. It may be noted that use of wire wound gradiometers and approaches based on electronic subtraction of sensor outputs to realize synthetic gradiometers have not been entirely satisfactory. We have designed a first order planar gradiometer with two planar loops in opposition with the Josephson weak links in the form of microbridges located at the centre. Bicrystal SrTiO3 substrates with a 24° misorientation angle were used for realizing the Josephson weak links using YBCO thin films, as well as HTS planar gradiometer coupled to a HTS SQUID sensor. The performance of these devices are evaluated.
{"title":"Development of planar first order gradiometer coupled to HTS SQUID sensor","authors":"L. S. Vaidhyanathan, D. K. Baisnab, R. Baskaran, M. Janawadkar","doi":"10.1109/ISPTS.2015.7220136","DOIUrl":"https://doi.org/10.1109/ISPTS.2015.7220136","url":null,"abstract":"The HTS SQUID sensors coupled to an on-chip integrated planar gradiometric pick-up loop were fabricated using highly reliable advanced micro-fabrication techniques such as deposition of superconducting thin films by Pulsed Laser Deposition (PLD), UV photolithography and RF ion beam etching. It may be noted that use of wire wound gradiometers and approaches based on electronic subtraction of sensor outputs to realize synthetic gradiometers have not been entirely satisfactory. We have designed a first order planar gradiometer with two planar loops in opposition with the Josephson weak links in the form of microbridges located at the centre. Bicrystal SrTiO3 substrates with a 24° misorientation angle were used for realizing the Josephson weak links using YBCO thin films, as well as HTS planar gradiometer coupled to a HTS SQUID sensor. The performance of these devices are evaluated.","PeriodicalId":6520,"journal":{"name":"2015 2nd International Symposium on Physics and Technology of Sensors (ISPTS)","volume":"61 1","pages":"310-312"},"PeriodicalIF":0.0,"publicationDate":"2015-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80277643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-03-07DOI: 10.1109/ISPTS.2015.7220074
R. Bhowmik, A. G. Lone, G. Vijayasri
The magneto-electronic properties have been demonstrated for a novel class of ferromagnetic semiconductors based on Ga doped a-Fe2O3 (hematite) system. The doping of the Ga atoms into the lattices of Fe sites of oc-Fe2O3 structure has been performed by chemical coprecipitation and mechanical alloying routes. Among the metal doped hematite systems, Ga doped oc-Fe2O3 system has been found as a good candidate for achieving simultaneous electric and magnetic field controlled magneto-electronic properties. The magnetic field dependent I-V characteristics and ferroelectric polarization, and ferromagnetic loop under electric field have suggested that Ga doped a-Fe2O3 system could be a potential candidate for the room temperature applications in spintronics devices, especially in magnetic sensors and switches as shown in this paper.
{"title":"Ga doped hematite (α-Fe2O3): A promising magnetic sensor material","authors":"R. Bhowmik, A. G. Lone, G. Vijayasri","doi":"10.1109/ISPTS.2015.7220074","DOIUrl":"https://doi.org/10.1109/ISPTS.2015.7220074","url":null,"abstract":"The magneto-electronic properties have been demonstrated for a novel class of ferromagnetic semiconductors based on Ga doped a-Fe2O3 (hematite) system. The doping of the Ga atoms into the lattices of Fe sites of oc-Fe2O3 structure has been performed by chemical coprecipitation and mechanical alloying routes. Among the metal doped hematite systems, Ga doped oc-Fe2O3 system has been found as a good candidate for achieving simultaneous electric and magnetic field controlled magneto-electronic properties. The magnetic field dependent I-V characteristics and ferroelectric polarization, and ferromagnetic loop under electric field have suggested that Ga doped a-Fe2O3 system could be a potential candidate for the room temperature applications in spintronics devices, especially in magnetic sensors and switches as shown in this paper.","PeriodicalId":6520,"journal":{"name":"2015 2nd International Symposium on Physics and Technology of Sensors (ISPTS)","volume":"39 1","pages":"22-26"},"PeriodicalIF":0.0,"publicationDate":"2015-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89255794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-03-07DOI: 10.1109/ISPTS.2015.7220100
S. Mehta, S. S. Suryavanshi, I. S. Mulla
Tungsten oxide is amongst the most widely used materials in electro-, photo-chromic applications. Recently tungsten oxide has been employed as sensing layer for detection of hazardous gases. In this work, we report synthesis of WO3 nanoparticles via a facile hydrothermal method using sodium tungstate and different organic acids (viz. citric acid, oxalic acid, malonic acid, and (L+) tartaric acid). We have investigated the effect/role of organic acid on the morphology and gas sensing properties. The X-ray diffraction (XRD) studies confirmed that citric acid and oxalic acid assisted routes give monoclinic structure (m-WO3) while malonic acid and (L+) tartaric acid give hexagonal structure (h-WO3). The nanoplate-like morphology was revealed by Scanning electron microscopy (SEM) analysis. The thick film of WO3 powder was deposited by using a screen printing technique. The gas response of thick films fired at 400°C/2h was studied. The change in the gas response of WO3 nanoplates for various concentrations and operating temperatures were studied for NOX, acetone, ethanol and ammonia vapors. In general, we observed response towards acetone, ethanol and ammonia vapors at higher operating temperature. However, the citric acid, oxalic acid and tartaric acid assisted WO3 exhibited good response for NOX at lower operating temperature (from 80°C-200°C). The gas response studies revealed that WO3 synthesized by citric acid assisted route exhibits highest sensitivity (S=77%) at 130°C towards NOX gas.
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