PDF Publication Title:
Text from PDF Page: 007
Energies 2022, 15, 6452 7 of 21 vibrational modes occurred at the same frequencies, meaning that contributions of the same ZrO2 polymorph were present in both materials. Tetragonal zirconia (D4h point group) was expected to exhibit six Raman active vibrational modes at the Γ point of the first Brillouin zone with A1g + 2B1g + 3Eg symmetries [78]. The frequencies of these modes were reported as 146 cm−1 (Eg), 270 cm−1 (A1g), 318 cm−1 (B1g), 458 cm−1 (Eg), 602 cm−1 (B1g) and 648 cm−1 (Eg) [79]. For the case of the monoclinic ZrO2 (C2h point group), group theory analysis predicted 18 Raman active modes, 9Ag + 9Bg [80], with frequencies reported at 179 cm−1 (Ag), 190 cm−1 (Ag), 224 cm−1 (Bg), 305 cm−1 (Ag), 334 cm−1 (Bg), 348 cm−1 (Ag), 381 cm−1 (Bg), 476 cm−1 (Ag), 505 cm−1 (Bg), 536 cm−1 (Bg), 556 cm−1 (Ag), 616 cm−1 (Bg), 637 cm−1 (Ag) and a non-indexed peak at 757 cm−1 [77,81]. By comparing the spectra of the two materials in Figure 2, we were able to identify that the vibrational modes matched those reported for both crystalline phases [77,81]. In particular, the bandwidth of the Raman lines in the as-synthesized material was likely to be due to the overlap of the vibrational signatures from the tetragonal and monoclinic ZrO2, as clearly identified by the presence of the 146 cm−1 and 265 cm−1 resonances and the bandshape asymmetry observed at 458 cm−1 and 648 cm−1, which were assigned to the tetragonal phase. In contrast with Figure 2a, no bands related to the tetragonal ZrO2 are visible in Figure 2b; however, its presence cannot be excluded. In addition, another band at 501 cm−1 (Bg) is visible, assigned to monoclinic ZrO2 [77,81]. Cubic zirconia exhibits a characteristic broad band mode centered at 625 cm−1 due to disordered oxygen sub-lattice. This vibrational mode is not visible in Figure 2a,b. Moreover, the absence of the cubic phase was already Energies 2022, 15, x FOR PEER REVIEW 8 of 23 expected since it is stable only at annealing temperatures near to ZrO2 melting point or at RT by doping processes [82]. No other bands were detected [83]. FFigiguurere22. .RRaammaannspspecetcrtaraofotfhtehesysnytnhtehseizseizdeZdrZOrOn2anaonpopwodwedrse:r(sa: )(ab)ebfoerfeoraendan(db)(abf)tearftcearlcianlactiinoantiaotn 2 at 8◦00 °C for 15 min. The black and orange vertical dash lines represent the expected frequencies for 800 C for 15 min. The black and orange vertical dash lines represent the expected frequencies for the the monoclinic and tetragonal ZrO2, respectively, and according to [77,79,81]. monoclinic and tetragonal ZrO2, respectively, and according to [77,79,81]. 33.1.1.2.2. .X--rraayyDififfrraacctitoionn XXRRDmeeaassuurreemeennttssweerereaalslosopperefroformrmeeddtotococnofinfrimrmthtehecrcyrsytsatlalilnlienephpahsaes/ep/phhaasseess oobbtatainineeddfrofrmomRamRamn sapnecstproescctoropsycmopeyasumremaseunrtesm. Aenstse.enAisn Fseigeunrein3a,Ftihgeuares-s3yan,thtehseizeads- ZrO nanopowderpresentsamixtureofZrO tetragonalandmonoclinicphases,consid- syn2thesized ZrO2 nanopowder presents a m2 ixture of ZrO2 tetragonal and monoclinic eringtheICDDcardnumbers00-037-1484and00-050-1089fortheZrO monoclinicand phases, considering the ICDD card numbers 00-037-1484 and 00-050-21089 for the ZrO2 tetragonal phases, respectively. monoclinic and tetragonal phases, respectively.PDF Image | Comparison between Solution-Based Synthesis Methods of ZrO2
PDF Search Title:
Comparison between Solution-Based Synthesis Methods of ZrO2Original File Name Searched:
energies-15-06452.pdfDIY PDF Search: Google It | Yahoo | Bing
Turbine and System Plans CAD CAM: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. More Info
Waste Heat Power Technology: Organic Rankine Cycle uses waste heat to make electricity, shaft horsepower and cooling. More Info
All Turbine and System Products: Infinity Turbine ORD systems, turbine generator sets, build plans and more to use your waste heat from 30C to 100C. More Info
CO2 Phase Change Demonstrator: CO2 goes supercritical at 30 C. This is a experimental platform which you can use to demonstrate phase change with low heat. Includes integration area for small CO2 turbine, static generator, and more. This can also be used for a GTL Gas to Liquids experimental platform. More Info
Introducing the Infinity Turbine Products Infinity Turbine develops and builds systems for making power from waste heat. It also is working on innovative strategies for storing, making, and deploying energy. More Info
Need Strategy? Use our Consulting and analyst services Infinity Turbine LLC is pleased to announce its consulting and analyst services. We have worked in the renewable energy industry as a researcher, developing sales and markets, along with may inventions and innovations. More Info
Made in USA with Global Energy Millennial Web Engine These pages were made with the Global Energy Web PDF Engine using Filemaker (Claris) software.
Sand Battery Sand and Paraffin for TES Thermo Energy Storage More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)