Atomically resolved structure and interface related phenomena in nano-scale modulated smart materials


Project Director: Dr. Corneliu Ghica

Abstract

Physical properties of advanced materials like ferroelectric and ferromagnetic materials, multilayered structures of semiconductors, shape memory alloys (SMA) result from the interaction between the micro- or nano-scale components (crystal grains, thin films), involving interface processes.  The importance of the interface phenomena and of the associated structural defects increases with the size reduction of the involved crystal grains or thin layers. Getting accurate structural information at and near the interface between the nanoscaled components (atomic structure of the interface, associated extended defects, strain fields) becomes mandatory in understanding and designing the physical properties of new materials. Advanced techniques of analytical electron microscopy along with consecrated structural and thermal analysis techniques using state-of-the-art equipments will be mainly employed for thorough microstructural investigations on two classes of materials for which interface phenomena play a crucial role: i. artificial multiferroics and ii. shape memory alloys.

The project specific objectives are:

  1. Atomic structure of interfaces and structural defects in artificial multiferroics.
  2. Strain field and composition mapping at atomic scale around interfaces and structural defects in artificial multiferroics.
  3. Correlation between structural phase transitions and strain fields in nanoscale modulated SMAs.
  4. Atomically resolved crystal structure in nanoscale modulated SMAs.
No.NameFunction
1Ghica CorneliuScientific Researcher 1, Project leader
2Nistor Leona CristinaScientific Researcher 1
3Valeanu MihaelaScientific Researcher 1
4Teodorescu Valentin SerbanScientific Researcher 1
5Vlaicu Aurel MihaiScientific Researcher 3
6Ghica DanielaScientific Researcher 3
7Maraloiu Valentin AdrianScientific Researcher
8Mercioniu Ionel FlorinelScientific Researcher
9Sofronie MihaelaScientific Researcher
10Chirila CristinaScientific Researcher
11Negrea Raluca FlorentinaPhD student
12Kuncser Andrei CristianMSc student
13Ion AntonTechnician
14Florescu VioricaTechnician

1. Semiquantitative interpretation of the atomic resolution STEM-HAADF images enabled us to evidence and characterize the atomic diffusion process across interfaces in epitaxial systems. A result obtained on the PZT-SRO interface in the case of a multilayered epitaxial deposition on STO substrate is illustrated in Figure 16. Given the proportionality relation between the differential scattering cross section of the electrons and the square of the atomic number Z, the high-resolution STEM image provides information of chemical nature. In the case of the analyzed sample we can say that the thin SRO layer shows a terminal Sr-O plane in contact with a Zr-Ti-O plane of PZT layer. Moreover, form the gradient of ADF signal it can be shown an atomic inter-diffusion limited to 7 atomic planes around the interface.

(a) STEM-HAADF image of the interface between PZT and SRO epitaxial thin layers;(b) Line profile of Z contrast along the direction indicated by red arrow in the image (a); (c) Mean value of the signal from ADF detector as a function of position relative to the interface, showing a process of atomic inter-diffusion inside a layer with thickness of 7 atomic planes around the interface.

2. Our complex HRTEM studies showed that the investigated SMA samples with a composition of the type Ni53Fe20Co2Ga25, Ni52Fe20Co2Ga26, Ni52Fe20Co3Al2Ga23 show a martensitic phase transition with the transition in a monoclinic deformed phase at the room temperature, which leads to the formation of hierarchical structural domains: i. Twins with 100 nm order width having pseudocubic {100} planes as twin planes; ii. The twins show a fine structure of fringes with a periodicity of 2 nm, corresponding to a structural modulation along [110]c pseudocubic direction based on a monoclinic deformed unit supercell, having pseudocubic (110) planes slipped parallel with the base plane. The monoclinic cell consists of 5 unit cubic cells overlapped along the [110]c direction in which atomic positions are displaced parallel with the base plane according to a quasi-sine law [8] which generates a structural modulation with a 2 nm periodicity (5M modulation).

(a) HRTEM image at low magnification at the borderline between the structural domains in a Ni53Co2Ga25Fe20 ultrafast cooled martensitic alloy, subject to a 1 h thermal treatment at 400 C. (b) experimental HRTEM image corresponding to the marked area in (a) which contains an inset of a simulated HRTEM image (B=[210]m, t=5 nm, Df=-30 nm)

 

 

 

 

 

 

D1. Andrei KUNCSER - participation in "EELS & EFTEM Course", 4-7 Februarie 2014 FELMI-ZFE, Graz University of Technology, Austria

D2. Dr. Adrian MARALOIU, participation in "EELS & EFTEM Course", 4-7 Februarie 2014 FELMI-ZFE, Graz University of Technology, Austria

D4. MSc thesis defended by Andrei KUNCSER at the University of Bucharest, Faculty of Physics.

D5. PhD thesis entitled „High-Resolution Transmission Electron Microscopy: atomic structure of the interfaces and of the extended defects in heterogeneous crystalline structures” publicly defended by Raluca Florentina NEGREA at the University of Bucharest, Faculty of Physics.

ISI Journal articles (cumulated FI 43.192, cumulated AIS 10.6, cumulated SRI 28.302)

A1. C. Ghica, R. F. Negrea, L. C. Nistor, C. F. Chirila, L. Pintilie, "Nanoscale monoclinic domains in epitaxial SrRuO3 thin films deposited by pulsed laser deposition", Journal of Applied Physics 116, 023516 (2014) (FI 2.183, AIS 0.7, SRI 1.546)

A2. D. Batalu, G. Aldica, S. Popa, L. Miu, M. Enculescu, R. F. Negrea, I. Pasuk, P. Badica, "High magnetic field enhancement of the critical current desity by Ge, GeO2 and GeC6H10O7 additions to MgB2", Scripta Materialia 82, 61-64 (2014) (FI 3.224, AIS 1.2, SRI 5.362)

A3. P. Badica, G. Aldica, M. Burdusel, S. Popa, R. F. Negrea, M. Enculescu, I. Pasuk and L. Miu, "Significant enhancement of the critical current density for cubic BN addition into ex situ spark plasma sintered MgB2", Superconductor Science and Technology 27, 095013 (2014) (FI 2.325, AIS 0.8, SRI 1.841)

A4. D. Ghica, M. Stefan, C. Ghica, G. E. Stan, "Evaluation of the Paramagnetic Impurities Segregation at Grain Boundaries in Nanostructured ZnO Films", ACS Applied Materials & Interfaces 6, 14231-14238 (2014) (FI 6.723, AIS 1.3, SRI 3.128)

A5. N.D. Scarisoreanu, F. Craciun, R. Birjega, A. Andrei, V. Ion, R.F. Negrea, C. Ghica, M. Dinescu, "Strain-induced long range ferroelectric order and linear electro-optic effect in epitaxial relaxor thin films", Journal of Applied Physics 116, 074106 (2014) (FI 2.183, AIS 0.7, SRI 1.546)

A6. G. Krishnan, R. F. Negrea, C. Ghica, G. H. ten Brink, B. J. Kooi, G. Palasantzas, "Exceptional thermal stability and synthesis of Mg based bimetallic nanoparticles for hydrogen storage", Nanoscale 6, 11963-11970 (2014) (FI 7.394, AIS 1.6, SRI 5.133)

A7. T. M. Dinh, A. Achour, S. Vizireanu, G. Dinescu, L. Nistor, K. Armstrong, D. Guay, D. Pech, „Hydrous RuO2/carbon nanowalls hierarchical structures for all-solid-state ultrahigh-energy-density micro-supercapacitors”, Nano Energy 10, 288-294 (2014) (FI 10.325, AIS 2.4, SRI 5.130)

A8. A. Kuncser, G. Schinteie, C. Ghica, S. Antohe, V. Kuncser, "Applicability of the Stoner-Wohlfarth Model for Ni-Fe Graded Thin Films", Journal of Superconductivity and Novel Magnetism 28, 965-969 (2015)

A9. R. F. Negrea, V. S. Teodorescu, C. Ghica, "Atomic scale elemental mapping of light elements in multilayered perovskite coatings", Applied Surface Science 315, 250-255 (2015) (FI 2.711, AIS 0.6, SRI 1.488)

A10. N. D. Scarisoreanu, F. Craciun, A. Moldovan, V. Ion, R. Birjega, C. Ghica, R. F. Negrea, M. Dinescu, "High permittivity (1-x)Ba(Zr0.2Ti0.8)O3 –x(Ba0.7Ca0.3)TiO3 (x = 0.45) epitaxial thin films with nanoscale phase fluctuations", ACS Applied Materials & Interfaces 7, 23984-23992 (2015) (FI 6.723, AIS 1.3, SRI 3.128)

 

International Conferences

C1. C. Ghica, R. F. Nergrea, L. C. Nistor, V. A. Maraloiu, C. F. Chirila, L. Pintilie, "Microstructural characterization of multilayered perovskite coatings for artificial multiferroics”, oral presentation at International Multidisciplinary Microscopy Congress InterM 2013, 10-13 Octombrie 2013, Antalya, Turcia

C2. C. Ghica, R. F. Negrea, L. C. Nistor, L. Pintilie, "Nanoscale Phase Transition in Strained SrRuO3 Thin Film", orat presentation at la 12th Europhysical Conference on Defects in Insulating Materials EURODIM 2014, July 13-19, 2014, Canterbury, UK

C3. R. F. Negrea, C. Ghica, L. C. Nistor, L. Pintilie, „Atomic scale STEM and EELS characterization of BaTiO3/SrRuO3/SrTiO3 ferroelectric heterostructure” poster at 12th Europhysical Conference on Defects in Insulating Materials EURODIM 2014, July 13-19, 2014, Canterbury, UK

C4. A. Kuncser, S. Antohe, C. Ghica, V. Kuncser, "Extended Stoner-Wohlfarth Model for Bi-dimensional Distributions of Easy Axes", poster presentation at International Conference on Superconductivity and Magnetism ICSM 2014, April 27 - Mai 02, 2014, Antalya, Turkey

C5. R. F. Negrea , C. Ghica, V. S. Teodorescu, V. A. Maraloiu, L. C. Nistor, "HRTEM/STEM characterization of interfaces and strain-related distortions in epitaxial perovskite heterostructures", poster presentation at 18-th International Microscopy Congress IMC 2014, September 7-12, 2014, Prague, Czech Republic

C6. C. Ghica, R. F. Negrea, V. S. Teodorescu, V. A. Maraloiu, L. C. Nistor, C. Chirila, L. Pintilie, "Quantitative HRTEM analysis of epitaxial perovskite multilayer on Si(001) single crystal substrate", poster presentation at 18-th International Microscopy Congress IMC 2014, September 7-12, 2014, Prague, Czech Republic

C7. R.F. Negrea, C. Ghica, V.S. Teodorescu, "Atomic scale elemental mapping of light elements in multilayered perovskite coatings", oral presentation at the 8th International Conference on Advanced Materials, ROCAM 2015, July 7-10, 2015, Bucharest, Romania

C8. A. Kuncser, C. Ghica, S. Antohe, V. Kuncser, "Micromagnetic vs. multi-component Stoner-Wohlafrth interpretation of magnetization reversal in magnetic nanosized systems", oral presentation at the 8th International Conference on Advanced Materials, ROCAM 2015, July 7-10, 2015, Bucharest, Romania

C9. C. Ghica, R. F. Negrea, V. S. Teodorescu, N. Scarisoreanu, R. Birjega, M. Dinescu, "QHRTEM investigation on growth evolution of the residual strain in epitaxial films", poster presentation at the European Congress and Exhibition on Advanced Materials and Processes EUROMAT 2015, September 20-24, 2015, Warsaw, Poland

C10. I. Mercioniu, A. M. Vlaicu, A. Kuncser, R. Negrea, C. Ghica, A. Mihailescu, A. Stefan, G. Ionescu, V. Manoliu "HRTEM Detailed Analysis of Oxides Structures of Y, Ta doped NiCrAl compounds for TBC”, poster presentation at the European Congress and Exhibition on Advanced Materials and Processes EUROMAT 2015, September 20-24, 2015, Warsaw, Poland

C11. R.F. Negrea C. Ghica, V.S. Teodorescu, C. Chirila,  "Atomic scale characterization of interfaces in ferroelectric epitaxial multilayers by STEM and EELS", poster presentation at the European Congress and Exhibition on Advanced Materials and Processes EUROMAT 2015, September 20-24, 2015, Warsaw, Poland

C12. C. Ghica, R.F. Negrea, V.S. Teodorescu, C.F. Chirila, L. Pintilie, “QHRTEM investigation on growth evolution of the residual strain in epitaxial films” poster presentation at the 6th International Conference on NANOstructures and nanomaterials SElf-Assembly NANOSEA 2016, July 3rd-8th, 2016 - Giardini Naxos, Italy

C13. C. Ghica, R. F. Negrea, V. S. Teodorescu, C. F. Chirila, N. D. Scarisoreanu, “On the evolution of the residual strain in thin epitaxial films by HRTEM quantification and nanoscale mapping”, oral presentation at 8th International Conference on Nanomaterials - Research & Application NANOCON 2016, October 19th-21st, 2016, Brno, Czech Republic

C14. R.F. Negrea, C. Ghica, “Atomic Scale STEM and EELS Characterization of Ferroelectric Structures Based on BaTiO3” poster presentation at 8th International Conference on Nanomaterials - Research & Application NANOCON 2016, October 19th-21st, 2016, Brno, Czech Republic

C15. R.F. Negrea, C. Ghica, ”Analytical TEM in strained systems”, oral presentation at Workshop on Advanced Analytical Technics of Transmission Electron Microscopy,  May 28th – June 2nd, Institut de Physique et Chimie des Matèriaux, Strasbourg, France

C16. A.C. Kuncser, „TEM Investigations & Micromagnetic simulations”, oral presentation at Workshop on Advanced Analytical Technics of Transmission Electron Microscopy,  May 28th – June 2nd, Institut de Physique et Chimie des Matèriaux, Strasbourg, France

C17. I.F. Mercioniu, „Sample preparation and characterisation using SEM-FIB facilities”, oral presentation at Workshop on Advanced Analytical Technics of Transmission Electron Microscopy,  May 28th – June 2nd, Institut de Physique et Chimie des Matèriaux, Strasbourg, France

C18. A.M. Vlaicu, „Oxidation dynamics in zyrconia-based thermal barrier coatings”, oral presentation at Workshop on Advanced Analytical Technics of Transmission Electron Microscopy,  May 28th – June 2nd, Institut de Physique et Chimie des Matèriaux, Strasbourg, France

C19. V. A. Maraloiu, „Biotransformations of magnetic nanoparticles in biological environments” oral presentation at Workshop on Advanced Analytical Technics of Transmission Electron Microscopy,  May 28th – June 2nd, Institut de Physique et Chimie des Matèriaux, Strasbourg, France

Organization of the „Workshop on Advanced Analytical Technics of Transmission Electron Microscopy” in collaboration with Institut de Physique et Chimie des Matériaux de Strasbourg, Département Surfaces-Interfaces during 28.05-02.06.2016 in Strasbourg, France.


PROJECTS/ NATIONAL PROJECTS


Back to top

Copyright © 2022 National Institute of Materials Physics. All Rights Reserved