FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2945032285> ?p ?o ?g. }

• W2945032285 abstract "This thesis presents Raman studies of Sodium iridates (Na2IrO3 and Na4Ir3O8), VO2, black phosphorus, Weyl (TaAs, TaP, NbP and NbAs) and Dirac (Cd3As2) semimetals under ex-treme conditions like low temperature (upto 4K), ultra high pressures (upto 30 GPa) and electrochemical top gating of nanodevices. Temperature-dependent Raman studies were car-ried out to look for Raman signatures of Kitaev quantum spin liquid state in sodium iridates. In-situ Raman measurements were done on electrochemically top-gated field effect transistor devices fabricated on phosphorene and VO2 nanofilms to show symmetry-dependent phonon renormalization in phosphorene and microscopic origin of insulator to metal transition in VO2 nanofilms. High pressure studies were carried out to look for electronic topological as well as structural phase transitions in black phosphorus, Weyl and Dirac semimetals. For structural characterization as a function of pressure, x-ray diffraction measurements using synchrotron source have been pursued. We provide an overview of our work on these systems chapter-wise. In Chapter 1, we give a brief introduction of the systems studied in this thesis, i.e. Sodium iridates (Na2IrO3 and Na4Ir3O8), VO2, black phosphorus, Weyl (TaAs, TaP, NbP and NbAs) and Dirac (Cd3As2) semimetals. A summary of main results is given at the end of this chapter. Chapter 2 gives a brief introduction to Raman scattering and Synchrotron x-ray diffrac-tion, followed by the effect of temperature and pressure on the lattice. Further, the experi-mental setups and techniques used in this thesis are discussed. In Chapter 3, we discuss our Raman results on Sodium iridates (Na2IrO3 and Na4Ir3O8). This chapter is divided into two parts. In Part 3.1, we present temperature dependent Raman results on single crystals of (Na1−xLix)2IrO3 (x = 0, 0.05 and 0.15) in the temperature range from 4K to 300K. Our study shows a polarization independent broad band at ∼ 2750 cm−1 with a large band-width of ∼ 1800 cm−1. For Na2IrO3 the broad band is seen for temperatures ≤ 200 K and persists inside the magnetically ordered state. For Li-doped samples, the intensity of this mode increases, shifts to lower energy, and persists to higher temperatures. Such a mode has been predicted recently as a signature of the Kitaev quantum spin liquid (QSL). We assign the observed broad band to be a signature of strong Kitaev-exchange correlations. The fact that the broad band persists even inside the magnetically ordered state (with Neel temperature TN ) suggests that dynamically fluctuating moments survive even below TN . This is further supported by our mean field calculations of our collaborators. The Raman response calculated in mean field theory shows that the broad band predicted for the QSL state survives in the magnetically ordered state near the zigzag-spin liquid phase boundary. A comparison with the theoretical model gives an estimate of the Kitaev exchange interaction parameter to be JK ≈ 57 meV. In Part 3.2, we present temperature dependent Raman…" @default.
• W2945032285 created "2019-05-29" @default.
• W2945032285 creator A5079206652 @default.
• W2945032285 date "2019-04-23" @default.
• W2945032285 modified "2023-09-24" @default.
• W2945032285 title "Iridates, Black Phosphorus, Weyl and Dirac Semimetals Under Extreme Conditions : Raman Study" @default.
• W2945032285 hasPublicationYear "2019" @default.
• W2945032285 type Work @default.
• W2945032285 sameAs 2945032285 @default.
• W2945032285 citedByCount "0" @default.
• W2945032285 crossrefType "dissertation" @default.
• W2945032285 hasAuthorship W2945032285A5079206652 @default.
• W2945032285 hasConcept C121332964 @default.
• W2945032285 hasConcept C169573571 @default.
• W2945032285 hasConcept C177909632 @default.
• W2945032285 hasConcept C181966813 @default.
• W2945032285 hasConcept C185592680 @default.
• W2945032285 hasConcept C192562407 @default.
• W2945032285 hasConcept C26873012 @default.
• W2945032285 hasConcept C2777208637 @default.
• W2945032285 hasConcept C2910973916 @default.
• W2945032285 hasConcept C40003534 @default.
• W2945032285 hasConcept C49040817 @default.
• W2945032285 hasConcept C62520636 @default.
• W2945032285 hasConceptScore W2945032285C121332964 @default.
• W2945032285 hasConceptScore W2945032285C169573571 @default.
• W2945032285 hasConceptScore W2945032285C177909632 @default.
• W2945032285 hasConceptScore W2945032285C181966813 @default.
• W2945032285 hasConceptScore W2945032285C185592680 @default.
• W2945032285 hasConceptScore W2945032285C192562407 @default.
• W2945032285 hasConceptScore W2945032285C26873012 @default.
• W2945032285 hasConceptScore W2945032285C2777208637 @default.
• W2945032285 hasConceptScore W2945032285C2910973916 @default.
• W2945032285 hasConceptScore W2945032285C40003534 @default.
• W2945032285 hasConceptScore W2945032285C49040817 @default.
• W2945032285 hasConceptScore W2945032285C62520636 @default.
• W2945032285 hasLocation W29450322851 @default.
• W2945032285 hasOpenAccess W2945032285 @default.
• W2945032285 hasPrimaryLocation W29450322851 @default.
• W2945032285 hasRelatedWork W1631569001 @default.
• W2945032285 hasRelatedWork W2001255875 @default.
• W2945032285 hasRelatedWork W2112646032 @default.
• W2945032285 hasRelatedWork W2249107397 @default.
• W2945032285 hasRelatedWork W2275871024 @default.
• W2945032285 hasRelatedWork W2331253364 @default.
• W2945032285 hasRelatedWork W2494734331 @default.
• W2945032285 hasRelatedWork W2553684133 @default.
• W2945032285 hasRelatedWork W2564227198 @default.
• W2945032285 hasRelatedWork W2732083800 @default.
• W2945032285 hasRelatedWork W2765188817 @default.
• W2945032285 hasRelatedWork W2788095854 @default.
• W2945032285 hasRelatedWork W2904161533 @default.
• W2945032285 hasRelatedWork W2914638871 @default.
• W2945032285 hasRelatedWork W2949106170 @default.
• W2945032285 hasRelatedWork W3035132447 @default.
• W2945032285 hasRelatedWork W3090973442 @default.
• W2945032285 hasRelatedWork W3099767660 @default.
• W2945032285 hasRelatedWork W3121904426 @default.
• W2945032285 isParatext "false" @default.
• W2945032285 isRetracted "false" @default.
• W2945032285 magId "2945032285" @default.
• W2945032285 workType "dissertation" @default.