PROPOSAL TO THE ISOLDE COMMITTEE – INTC/P258-Addendum 1 Study of Local Correlations of Magnetic and Multiferroic Compounds Aveiro 1 , L’ Aquila 2 , Lisboa 3 , Moscow 4 , Orsay 5 , Porto 6 , Sacavém 7 , Stuttgart 8 , Tokyo 9 , Tsukuba 10 , Vila Real 11 and the ISOLDE/CERN 12 Spokesman: V. S. Amaral Contact person: K. Johnston E. Alves 7 , J.S. Amaral 1 , V.S. Amaral 1 , L.M. Amorim 7 , J.P. Araújo 6 , N.A. Babushkina 4 , M. Baptista 7,6 , J.G. Correia 7,12 , A. Fenta 1 , J.N. Gonçalves 1 , H. Haas 7 , H.-U. Habermeier 8 , K. Johnston 12 , A. L. Kholkin 1 , A.M.L. Lopes 3 , A.A. Lourenço 1 , T.M. Mendonça 6 , 12 , G. Oliveira 3,6 , S. Picozzi 2 , M.R. Silva 3 , J.B. Sousa 6 , A. Stroppa 2 , R. Suryanarayanan 5 , P.B. Tavares 11 , Y. Tokura 9 , Y. Tomioka 10 , J.M. Vieira 1
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PROPOSAL TO THE ISOLDE COMMITTEE – INTC/P258-Addendum 1
Study of Local Correlations of Magnetic
andMultiferroic CompoundsAveiro1, L’ Aquila2, Lisboa3, Moscow4, Orsay5,
Porto6, Sacavém7, Stuttgart8, Tokyo9, Tsukuba10, Vila Real11 and the ISOLDE/CERN12
Spokesman: V. S. Amaral
Contact person: K. Johnston
E. Alves7, J.S. Amaral1, V.S. Amaral1, L.M. Amorim7, J.P. Araújo6, N.A. Babushkina4, M. Baptista7,6, J.G. Correia7,12, A. Fenta1, J.N. Gonçalves1, H. Haas7, H.-U. Habermeier8, K. Johnston12, A. L. Kholkin1, A.M.L. Lopes3, A.A. Lourenço1, T.M. Mendonça6,12, G. Oliveira3,6, S. Picozzi2, M.R. Silva3, J.B. Sousa6, A. Stroppa2, R. Suryanarayanan5, P.B. Tavares11, Y. Tokura9, Y. Tomioka10, J.M. Vieira1
Ground State of these systems and interactions challenges
the scientific community understanding
Strong correlated electron systems:
Subtle entanglement of spin, charge, orbital and lattice degrees of
freedom
Give rise to phenomena likeHTC SuperconductivityColossal magnetoresistanceCharge Ordered/Orbital Ordered
Complex multi-scale world with:Intrinsic InhomogeneitiesClusters or stripes Phase segregationMultiferroic behaviour
Local Correlations of Magnetic and Multiferroic Compounds
Gigantic response upon external stimulation
Ability to couple multiple orders
Competing Orders
Ferromagnetic/Ferroelectric/Ferroelastic/
Charge/Orbital
Additional degree of freedom in materials design leading to
Potential applications for multifunction device
Local Correlations of Magnetic and Multiferroic Compounds
Subjects to be Studied
1. Local environment in multiferroic compounds
2. Local distortions, polaron correlations and dynamics, magnetostructural effects near magnetic phase transitions
Local Correlations of Magnetic and Multiferroic Compounds
1. Local environment in multiferroic compounds
Local Correlations of Magnetic and Multiferroic Compounds
In most of the cases the microscopic origin of magneto-electric coupling still left unclear and... other open questions remain...
Is there a critical dimension below which the ferroelectricity or the magnetoelectric coupling will disappear or change in nature?
Is there a way to elucidate a local effect?
Picozzi &
Ederer, 2009
1. Local environment in multiferroic compounds
Local Correlations of Magnetic and Multiferroic Compounds
An extensive study of the hyperfine interactions in a series of hexagonal and orthorhombic rare-earth manganites (RMnO3, R= Nd, Sm, Eu, Gd, Tb, Ho, Y, Er, Lu) was performed in IS487
Tania Mendonça PhD Thesis (2012)
Non centro-symmetric P63cm space group in the hexagonal crystalline structure at RT.
A structural transition to the centro-symmetric P63/mmc space group occurs at ~1310K.
Paraelectric to the ferroelectric phase transition at lower temperatures, TFE~833K.
coexistence of two distinct local environments in all temperature range.
High temperature crystalline structure allows only one nonequivalent rare-earth site.
Minor EFG2 might be due to a distortion of the Er 4a site, whose contribution to the ferroelectric ordering of this compound shall be investigated
EFG in ErMnO3
1. Local environment in multiferroic compounds
Local Correlations of Magnetic and Multiferroic Compounds
Cr3+ ions dynamic off-centering in CdCr2S4 spinel leading to magneto-electric clusters (T>Tc,~85K)
- PAC technique using the 111In111Cd probeCoexistence of two local environments . Cd probes at Cd (30 %) and Cr (70 %).
Nat Mat ( submitted) Dynamic attenuation
1. Local environment in multiferroic compounds
Local Correlations of Magnetic and Multiferroic Compounds
Cr3+ ions dynamic off-centering in CdCr2S4 spinel leading to magneto-electric clusters
using the 117Cd117In probe
(117Cd probe replaces only the Cd position)
With cubic environment
EFG=0
Nat Mat ( submitted)
1. Local environment in multiferroic compounds
Local Correlations of Magnetic and Multiferroic Compounds
Cr3+ ions dynamic off-centering in CdCr2S4 spinel leading to magneto-electric clusters
Presence of a dynamic state on simultaneously polar and magnetic clusters, arising from the atomic off-center displacement of Cr3+ ions above Tc
Cr3+ ion role on the onset of local polar distortions, activated by thermal mechanism.
Atomic displacement mechanism drives the relaxor behavior in the PM regime
Pair Distribution Fn:Cr off centering
Nat Mat( submitted)
1. Local environment in multiferroic compounds
Local Correlations of Magnetic and Multiferroic Compounds
Relation between the electric polarization (P) and the electric field gradient (EFG) in ferroelectrics and multiferroics AND hyperfine HMF: local quantitative “description” of MF
Vzz at the A site as a function of P2
Coefficients of quadratic term of Vzz(P), at the A site, for a series of materials with the perovskite structure, as a function of atomic number ZA.
How can we relate EFG and Electric polarization ?An ab-initio study calculating bothin ABO3 (changing deformation)
1. Local environment in multiferroic compounds
Local Correlations of Magnetic and Multiferroic Compounds
Relation between the electric polarization (P) and the electric field gradient (EFG) in ferroelectrics and multiferroics AND hyperfine HMF: local quantitative “description” of MF
In YMn2O5 Mn4+ ions occupy the center of oxygen octahedra and Mn3+ ions at pyramid dimers
the FE polarization results purely from the spindependent Mn2-O-Mn1 hybridization and is due entirely to a redistribution of valence charge.
1. Local environment in multiferroic compounds
Local Correlations of Magnetic and Multiferroic Compounds
Relation between the electric polarization (P) and the electric field gradient (EFG) in ferroelectrics and multiferroics AND hyperfine HMF: local quantitative “description” of MF
When polarization appears without distortion: EFG and Electric polarization/Magnetic HF are related?ab-initio study in AB2O5 (changing magnetic state drives polarization)
-10 -8 -6 -4 -2 0 2 4 6-8
-6
-4
-2
0
2
4
6
8
10
12
F AF
HF
(T
)
Vzz (10^21 V/m^2)
YMn2O
5 Feromagnetic and Anti-Ferromagnetic
AF splitting
a) Charge-order induced or magnetically driven MF in RMnO3 (R= trivalent lanthanides) manganites, RNiO3 nickelates, MCrO2 (M=Cu, Ag) chromites and chromium spinels DCr2O4, (D=Mg, Cd, Zn, Hg). New case studies of: RMn2O5 (R=Y,Lu) mixed valence manganites and DMnO3divalent (D=Ca/Ba/Sr) perovskite manganites
b) MF where magnetism and ferroelectricity (FE) have distinct origins: RMnO3 (R=Y,Lu) lattice distortion provides the coupling to the spin system through magnetostriction ,BiFeO3 ferrite and variants, where FE is due to Bi lone pairs.
c) First-principle validation of relation between the electric polarization (P) and the electric field gradient (EFG), direct local probe of polarization. Ionic displacement and electronic contributions to EFG/P in Sr/Ba/CaMnO3
Local Correlations of Magnetic and Multiferroic Compounds
PAC studies: 111mCd (49 m) 111Cd 117Cd(2.4h) 117In and 111Ag(7.45d) 111Cd 199mHg 199Hg, 77Se 77Brand 48Cr 48V
1. Local environment in multiferroic compounds
Subjects to be Studied
1. Local environment in multiferroic compounds
2. Local distortions, polaron correlations and dynamics, magnetostructural effects near magnetic phase transitions
Local Correlations of Magnetic and Multiferroic Compounds
15
TC,i = 42.3-43.5 CTC,d = 30-32.6 CΔThysteresis = 9.7-13.5 C
Red: heatingBlue: coolingWhite: mix run (h&c)
At a given T, the hyperfine field is the same,
irrespective of cooling or heating the sample.
MnAs PhasesLow temperatureHexagonal structure (NiAs-type)Ferromagnetic metal
Orthorhombic structure (MnP-type), Paramagnetic
2. Local distortions, polaron correlations and magnetostructural effects
a) an extension of a previous study in ferromagnetic insulator samples to ferromagnetic metallic (in the paramagnetic state) and to less distorted perovskites (rhombohedral). Systems to be studied include: 18O/16O isotopically modified Sm1-xSrxMnO3 and
doped SrTiO3 samples.
b) magneto-structural changes in first-order magnetic phase transition in Mn pnictides, Ni2MnGa and related systems.
c) New case study of magnetic frustration reduction by local deformations in spin-ice systems, such as DCr2O4, (D=Mg, Cd,
Zn, Hg) at low temperatures (<20K).
Local Correlations of Magnetic and Multiferroic Compounds
PAC studies: 111mCd (49 m) 111Cd 117Cd(2.4h) 117In and 111Ag(7.45d) 111Cd 77Se 77Br
Experimental Facilities:Sample production and characterisation
•X-ray powder and single crystal diffraction: Aveiro, Porto•Scanning Electron Microsc. (SEM) with EDX: Aveiro,Porto, Vila Real•Transmission Electron Microscopy (HRTEM): Aveiro, Stuttgart•Rutherford Backscattering/Channeling : Lisboa/Sacavém.•Magnetic and Electrical properties: Aveiro, Orsay, Porto, Stuttgart , Tokyo/Tsukuba and CERN/ISOLDE
Laboratory Family ofsamples
Type of samples
Aveiro/Porto/ Vila Real
Moscow Orsay Stuttgart Tokyo and Tsukuba
RMnO3
+RMn2O5
+(Ca/Ba/Sr)MnO33
Pellets Solid State Reaction
Solid State Reaction - Solid State Reaction
BiFeO3 Pellets Solid State Reaction
La1-x(Ca/Sr)xMnO3 Pellets Solid State Reaction
La/Pr1-x(Ca/Sr)xMnO3
S. Crystals
Czochralski
Czochralski
above Thin films sputtering Pulsed Laser Ablation
DCr2X4 Pellets Solid State Reaction
Sm1-xSrxMnO316O and 18O
Pellets Solid State Reaction
RNiO3 Pellets Solid State Reaction
Mn pnictides+Ni2MnGa
Pellets arc melting
¨ Both the g-g and e--g PAC techniques are well established at ISOLDE
¨ g-g PAC spectrometer
4K up to 1100 K under gas flow.¨ e--g PAC spectrometer
25K up to 873 K under vacuum.
Nuclear techniques with radioactive isotopes: Perturbed Angular Correlations- PAC
Results from IS487 PhD/MSc thesis associated to work performed in IS487 (4+3)
João Amaral: PhD in 2005-2009: Continued Pos-Doc 2010-2016
Tânia Mendonça: PhD in 2006-2012: Working at Isolde (Target Group)
João Gonçalves: PhD in 2008-2011: Continued Pos-Doc 2012-2018
Célia Sousa: PhD 2008-2011: Continued Pos-Doc 2012-2018
Gonçalo Oliveira: MSc in 2009, PhD starting 2012
Marcelo Baptista Barbosa: MSc in 2010, PhD started 2011
João Horta Belo, MSc in 2010, PhD started 2011
Abel Fenta, MSc in 2011, PhD starting 2012
Results from IS487 Manuscripts in International Journals (5+2 submitted+3 in final preparation) First principles calculations of hyperfine parameters on the Ca manganite with substitutional Cd -modeling of a PAC experiment J. N. Gonçalves, H. Haas, A. M. L. Lopes, V. S. Amaral, J. G. Correia. Journal of Magnetism and Magnetic Materials ,322, 1170-1173 (2010) Perturbed Angular Correlations Investigations on YMnO3 Multiferroic ManganiteT.M. Mendonça, A.M.L. Lopes, J.N. Gonçalves, J.G. Correia, P.B. Tavares, V.S. Amaral, C. Darie, J.P. Araújo Hyperfine Interactions 197,83 (2010) Magnetic hyperfine field at Cr site in AgCrO2 given by perturbed angular correlationsG.N.P. Oliveira, A.M.L. Lopes, J.P. Araújo, T.M. Mendonça, J. Agostinho Moreira, A. Almeida, V.S. Amaral, J.G. Correia Hyperfine Interactions 197,123 (2010) Hyperfine Interactions in MnAs studied by Perturbed Angular Correlations of -Rays using the probe 77Br77Se and first principles calculations for MnAs and other Mn pnictidesJ. N. Gonçalves, V. S. Amaral, J. G. Correia, A. M. L. Lopes Physical Review B, 83, 104421 (2011) Local distortions in multiferroic AgCrO2 Triangular Spin LatticeA.M.L. Lopes, G.N.P. Oliveira, T.M. Mendonça, J. Agostinho Moreira, A. Almeida, J.P. Araújo, V.S. Amaral, J.G. Correia Physical Review B, 84, 014434 (2011)
Synthesis, Characterization and Local Probe Studies in Magnetoelectric AgCrO2
G.N.P. Oliveira, A.M.L. Lopes, J.P. Araújo, T.M. Mendonça, J. Agostinho Moreira, A. Almeida, V.S. Amaral, J.G. Correia,Physica Status Solidi C (submitted) Cr3+ ions dynamic off-centering in CdCr2S4 leading to magneto-electric clustersGonçalo Oliveira, André Pereira, Armandina M. L. Lopes, João Amaral, A. M. dos Santos, T.M. Mendonça, Celia Sousa, Yan Ren, Vitor Amaral, Guilherme Correia,, João Pedro Araújo Nat Mat ( submitted)Ferroelectricity and Electric Field Gradients: an ab-initio studyJ. N. Gonçalves, A. Stroppa, V. S. Amaral, J. G. Correia, T. Butz, and S. PicozziPhysical Review B (to be submitted) Hyperfine local probe study of alkaline-earth manganites BaMnO3 and SrMnO3
J. N. Gonçalves, V. S. Amaral, J. G. Correia, H. Haas, A. M. L. Lopes, J. P. Araújo, P.B. Tavares.Physical Review (to be submitted) Hyperfine parameters from first-principles in rare-earth multiferroic hexagonal manganites RMnO3 (R = Y, Ho, Er, Lu).J. N. Gonçalves, V. S. Amaral, J. G. CorreiaPhysical Review B (to be submitted)
Oral Communications to International conferences(15 ;4 invited)Posters in International to International conferences Conferences (9)
