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Mockuté, Aurelija
##### Publications (10 of 11) Show all publications
Dahlqvist, M., Ingason, A. S., Alling, B., Magnus, F., Thore, A., Petruhins, A., . . . Rosén, J. (2016). Magnetically driven anisotropic structural changes in the atomic laminate Mn2GaC. Physical Review B, 93(1), 014410
Open this publication in new window or tab >>Magnetically driven anisotropic structural changes in the atomic laminate Mn2GaC
2016 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 93, no 1, p. 014410-Article in journal (Refereed) Published
##### Abstract [en]

Inherently layered magnetic materials, such as magnetic M(n+1)AX(n) (MAX) phases, offer an intriguing perspective for use in spintronics applications and as ideal model systems for fundamental studies of complex magnetic phenomena. The MAX phase composition M(n+1)AX(n) consists of M(n+1)AX(n) blocks separated by atomically thin A-layers where M is a transition metal, A an A-group element, X refers to carbon and/or nitrogen, and n is typically 1, 2, or 3. Here, we show that the recently discovered magnetic Mn2GaC MAX phase displays structural changes linked to the magnetic anisotropy, and a rich magnetic phase diagram which can be manipulated through temperature and magnetic field. Using first-principles calculations and Monte Carlo simulations, an essentially one-dimensional (1D) interlayer plethora of two-dimensioanl (2D) Mn-C-Mn trilayers with robust intralayer ferromagnetic spin coupling was revealed. The complex transitions between them were observed to induce magnetically driven anisotropic structural changes. The magnetic behavior as well as structural changes dependent on the temperature and applied magnetic field are explained by the large number of low energy, i.e., close to degenerate, collinear and noncollinear spin configurations that become accessible to the system with a change in volume. These results indicate that the magnetic state can be directly controlled by an applied pressure or through the introduction of stress and show promise for the use of Mn2GaC MAX phases in future magnetoelectric and magnetocaloric applications.

##### Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2016
##### National Category
Condensed Matter Physics
##### Identifiers
urn:nbn:se:liu:diva-124463 (URN)10.1103/PhysRevB.93.014410 (DOI)000367779000005 ()
##### Note

Funding Agencies|European Research Council under the European Communities Seventh Framework Programme (FP7)/ERC Grant [258509]; Swedish Research Council (VR) [642-2013-8020, 621-2011-4417]; KAW Fellowship program; SSF synergy grant FUNCASE; VR Grant [621-2011-4426]; Russian Federation Ministry for Science and Education [14.Y26.31.0005]; Tomsk State University Academic D. I. Mendeleev Fund Program

Available from: 2016-02-02 Created: 2016-02-01 Last updated: 2017-11-30
Karlsson, L., Birch, J., Mockuté, A., Sigurdur Ingason, A., Ta, H. Q., Rummeli, M. H., . . . Persson, P. O. Å. (2016). Residue reduction and intersurface interaction on single graphene sheets. Carbon, 100, 345-350
Open this publication in new window or tab >>Residue reduction and intersurface interaction on single graphene sheets
2016 (English)In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 100, p. 345-350Article in journal (Refereed) Published
##### Abstract [en]

Large regions of pristine graphene are essential to applications which rely on the ideal graphene properties. Common methods for transferring chemical vapour deposition grown graphene to suitable substrates leaves metal oxide particles and poly(methyl methacrylate) (PMMA) residues on opposing surfaces, which degrade the properties. A common method to reduce the residues include annealing in vacuum or in argon, however, residues remain on the graphene sheet. The present investigation reports on the metal oxide particle ripening and PMMA decomposition on a single graphene sheet during in-situ annealing up to 1300 degrees C in a transmission electron microscope. It is shown that the PMMA residues are increasingly reduced at elevated temperatures although the reduction is strongly correlated to the metal oxide particle coverage on the opposing graphene surface. This is shown to occur as a consequence of an electrostatic interaction between the residues and that this prevents the establishment of large clean areas. (C) 2016 Elsevier Ltd. All rights reserved.

##### Place, publisher, year, edition, pages
Pergamon Press, 2016
##### National Category
Physical Sciences
##### Identifiers
urn:nbn:se:liu:diva-126123 (URN)10.1016/j.carbon.2016.01.007 (DOI)000369961400040 ()
##### Note

Funding Agencies|Swedish Research Council [621-2012-4359, 622-2008-405, 642-2013-8020]; Olle Engkvist foundation; Knut and Alice Wallenbergs Foundation; European Research Council [258509]; IBS Korea [IBS-RO11-D1]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [SFO-Mat-LiU 2009-00971]

Available from: 2016-03-15 Created: 2016-03-15 Last updated: 2017-11-30Bibliographically approved
Mockuté, A., Lu, J., Moon, E. J., Yan, M., Anasori, B., May, S. J., . . . Rosén, J. (2015). Solid Solubility and Magnetism upon Mn Incorporation in the Bulk Ternary Carbides Cr2AlC and Cr2GaC. Materials Research Letters, 3(1), 16-22
Open this publication in new window or tab >>Solid Solubility and Magnetism upon Mn Incorporation in the Bulk Ternary Carbides Cr2AlC and Cr2GaC
2015 (English)In: Materials Research Letters, ISSN 2166-3831, Vol. 3, no 1, p. 16-22Article in journal (Refereed) Published
##### Abstract [en]

Herein, we report on the bulk synthesis of (Cr1-xMnx)(2)AlC and (Cr1-yMny)(2)GaC MAX phases. Scanning electron and transmission electron microscopy, in combination with energy-dispersive X-ray spectroscopy performed locally on MAX phase grains, revealed x and y to be 0.06 (3 at%) and 0.3 (15 at%), respectively. The introduction of Mn into the structure did not result in appreciable changes in the c-lattice constants. Vibrating sample magnetometry measurements suggest that bulk (Cr0.7Mn0.3)(2)GaC may be magnetic.

##### Place, publisher, year, edition, pages
Taylor & Francis, 2015
##### Keywords
MAX Phases, Solid Solution, Bulk Synthesis, Magnetism
##### National Category
Physical Sciences
##### Identifiers
urn:nbn:se:liu:diva-127069 (URN)10.1080/21663831.2014.944676 (DOI)000372215500003 ()
##### Note

At the time for thesis presentation publication was in status: Manuscript,

At the time for thesis presentation manuscript was named: Solid solubility and magnetism upon Mn incorporation in bulk Cr2AlC and Cr2GaC MAX phases

Funding Agencies|European Research Council under the European Communitys Seventh Framework Programme [258509]; Swedish Research Council (VR) [621-2012-4425, 642-2013-8020]; Knut and Alice Wallenberg (KAW) Academy Fellowship Program; SSF synergy grant FUNCASE Functional Carbides and Advanced Surface Engineering

Available from: 2016-04-13 Created: 2016-04-13 Last updated: 2016-12-28Bibliographically approved
Dahlqvist, M., Alling, B., Ingason, P., Magnus, F., Thore, A., Petruhins, A., . . . Rosén, J. (2014). Complex magnetism in nanolaminated Mn2GaC.
Open this publication in new window or tab >>Complex magnetism in nanolaminated Mn2GaC
##### Abstract [en]

We have used first-principles calculations and Heisenberg Monte Carlo simulations to search for the magnetic ground state of Mn2GaC, a recently synthesized magnetic nanolaminate. We have, independent on method, identified a range of low energy collinear as well as non-collinear magnetic configurations, indicating a highly frustrated magnetic material with several nearly degenerate magnetic states. An experimentally obtained magnetization of only 0.29 per Mn atom in Mn2GaC may be explained by canted spins in an antiferromagnetic configuration of ferromagnetically ordered sub-layers with alternating spin orientation, denoted AFM[0001]$\smal\text{A}\atop\text{4}$. Furthermore, low temperature X-ray diffraction show a new basal plane peak appearing upon a magnetic transition, which is consistent with the here predicted change in inter-layer spacing for the AFM[0001]$\smal\text{A}\atop\text{4}$ configuration.

##### National Category
Physical Sciences
##### Identifiers
urn:nbn:se:liu:diva-104760 (URN)
Available from: 2014-02-25 Created: 2014-02-25 Last updated: 2017-11-03Bibliographically approved
Mockuté, A., Persson, P. O., Lu, J., Ingason, A. S., Magnus, F., Olafsson, S., . . . Rosén, J. (2014). Structural and magnetic properties of (Cr1-xMnx)(5)Al-8 solid solution and structural relation to hexagonal nanolaminates. Journal of Materials Science, 49(20), 7099-7104
Open this publication in new window or tab >>Structural and magnetic properties of (Cr1-xMnx)(5)Al-8 solid solution and structural relation to hexagonal nanolaminates
2014 (English)In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 49, no 20, p. 7099-7104Article in journal (Refereed) Published
##### Abstract [en]

Electron microscopy is used to reveal the competitive epitaxial growth of bcc structure (Cr1-x Mn (x) )(5)Al-8 and (Cr1-y Mn (y) )(2)AlC [M (n+1)AX (n) (MAX)] phase during both magnetron sputtering and arc deposition. X-ray diffraction theta-2 theta measurements display identical peak positions of (000n)-oriented MAX phase and (Cr1-x Mn (x) )(5)Al-8, due to the interplanar spacing of (Cr1-x Mn (x) )(5)Al-8 that matches exactly half a unit cell of (Cr1-y Mn (y) )(2)AlC. Vibrating sample magnetometry shows that a thin film exclusively consisting of (Cr1-x Mn (x) )(5)Al-8 exhibits a magnetic response, implying that the potential presence of this phase needs to be taken into consideration when evaluating the magnetic properties of (Cr, Mn)(2)AlC.

##### Place, publisher, year, edition, pages
Springer Verlag (Germany), 2014
##### National Category
Physical Sciences
##### Identifiers
urn:nbn:se:liu:diva-109870 (URN)10.1007/s10853-014-8416-8 (DOI)000339963800028 ()
##### Note

Funding Agencies|European Research Council under the European Communities Seventh Framework Programme (FP7)/ERC [258509]; Swedish Research Council [642-2013-8020]; KAW Fellowship program; Swedish Research Council; Knut and Alice Wallenberg Foundation; SSF Synergy Grant FUNCASE Functional Carbides and Advanced Surface Engineering; Carl Trygger Foundation

Available from: 2014-08-28 Created: 2014-08-28 Last updated: 2017-12-05
Mockuté, A., Persson, P. O., Magnus, F., Ingason, A. S., Olafsson, S., Hultman, L. & Rosén, J. (2014). Synthesis and characterization of arc deposited magnetic (Cr,Mn)2AlC MAX phase films. Physica Status Solidi. Rapid Research Letters, 8(5), 420-423
Open this publication in new window or tab >>Synthesis and characterization of arc deposited magnetic (Cr,Mn)2AlC MAX phase films
2014 (English)In: Physica Status Solidi. Rapid Research Letters, ISSN 1862-6254, E-ISSN 1862-6270, Vol. 8, no 5, p. 420-423Article in journal (Refereed) Published
##### Abstract [en]

(Cr1-xMnx)2AlC MAX phase thin films were synthesized by cathodic arc deposition. Scanning transmission electron microscopy including local energy dispersive X-ray spectroscopy analysis of the as-deposited films reveals a Mn incorporation of 10 at.% in the structure, corresponding to x = 0.2. Magnetic properties were characterized with vibrating sample magnetometry, revealing a magnetic response up to at least room temperature, thus verifying previous theoretical predictions of an antiferromagnetic or ferromagnetic ground state for Cr2AlC upon alloying with Mn.

##### Place, publisher, year, edition, pages
Wiley-Blackwell, 2014
Natural Sciences
##### Identifiers
urn:nbn:se:liu:diva-96998 (URN)10.1002/pssr.201409087 (DOI)000336495000009 ()
Available from: 2013-09-02 Created: 2013-09-02 Last updated: 2017-12-06Bibliographically approved
Mockutė, A. (2014). Synthesis and Characterization of New MAX Phase Alloys. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Synthesis and Characterization of New MAX Phase Alloys
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
##### Abstract [en]

This Thesis explores synthesis and characterization of new MAX phase alloys (M = early transition metal, A = A-group element, and X = C or N), based on incorporation of M and X elements previously not considered. My primary focus is on M = Mn for attaining magnetic properties, and on X = O for potential tuning of the transport properties. A recent theoretical study predicted (Cr1-xMnx)2AlC MAX phase to be a stable magnetic nanolaminate. I aimed at realizing this material and through a combinatorial approach based on magnetron sputtering from elemental targets, the first experimental evidence of Mn incorporation (x = 0.16) in a MAX phase is presented. The corresponding MAX phase was also synthesized using cathodic arc film deposition (x = 0.20) and bulk synthesis methods (x = 0.06). The primary characterization techniques were X-ray diffraction and high-resolution (scanning) transmission electron microscopy in combination with energy dispersive X-ray spectroscopy and/or electron energy loss spectroscopy, to obtain a precise local quantification of the MAX phase composition and to perform lattice resolved imaging. For epitaxial film growth of (Cr1-xMnx)2AlC, evidence is presented for the formation of (Cr1-yMny)5Al8, exhibiting a bcc structure with an interplanar spacing matching exactly half a unit cell of the hexagonal MAX phase. Consequently, routinely performed X-ray diffraction symmetric θ-2θ measurements result in peak positions that are identical for the two phases. As (Cr1-yMny)5Al8 is shown to display a magnetic response, its presence needs to be taken into consideration when evaluating the magnetic properties of the MAX phase. Methods  to distinguish between (Cr1-yMny)5Al8 and (Cr1-xMnx)2AlC are also suggested. As different A-element in the MAX phase is theoretically predicted to influence phase stability, attainable level of Mn  incorporation, as well as magnetic properties, thin films of (Cr0.75Mn0.25)2GeC and bulk (Cr0.7Mn0.3)2GaC have also been synthesized. Vibrating sample magnetometry measurements display a magnetic response for all these materials, identifying (Cr,Mn)2AlC, (Cr,Mn)2GeC, and (Cr,Mn)2GaC as the first magnetic MAX phases. The results presented in this Thesis show that A = Al displays the highest magnetic transition temperature (well above room temperature) and A = Ga allows the highest Mn content. The attainable O incorporation in Ti2Al(C1-xOx)MAX phase was explored by arc deposition of Ti2AlC1-y thin films under high vacuum conditions, and solid-state reactions following deposition of understoichiometric TiCz on Al2O3. Ti2Al(C1-xOx)thin films with up to 13 at.% O (x = 0.52) were synthesized, and O was shown to occupy the C lattice site. The obtained O concentration is enough to allow future experimental investigations of the previously suggested (from theory) substantial change in anisotropic electronic properties with increasing O content. The experimental results obtained in this Thesis expand the MAX phase definition and the materials characteristics into new research areas, towards further fundamental understanding and functionalization.

##### Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1573
Natural Sciences
##### Identifiers
urn:nbn:se:liu:diva-104829 (URN)10.3384/diss.diva-104829 (DOI)978-91-7519-407-3 (ISBN)
##### Supervisors
Available from: 2014-02-27 Created: 2014-02-27 Last updated: 2016-12-28Bibliographically approved
Ingason, A. S., Mockuté, A., Dahlqvist, M., Magnus, F., Olafsson, S., Arnalds, U. B., . . . Rosén, J. (2013). Magnetic Self-Organized Atomic Laminate from First Principles and Thin Film Synthesis. Physical Review Letters, 110
Open this publication in new window or tab >>Magnetic Self-Organized Atomic Laminate from First Principles and Thin Film Synthesis
2013 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 110Article in journal (Refereed) Published
##### Abstract [en]

he first experimental realization of a magnetic Mn+1AXn (MAX) phase, (Cr0.75Mn0.25)2GeC, is presented, synthesized as a heteroepitaxial single crystal thin film, exhibiting excellent structural quality. This self-organized atomic laminate is based on the well-known Cr2GeC, with Mn, a new element in MAX phase research, substituting Cr. The compound was predicted using first-principles calculations, from which a variety of magnetic behavior is envisaged, depending on the Mn concentration and Cr/Mn atomic configuration within the sublattice. The analyzed thin films display a magnetic signal at room temperature.

##### Place, publisher, year, edition, pages
American Physical Society, 2013
Natural Sciences
##### Identifiers
urn:nbn:se:liu:diva-104824 (URN)10.1103/PhysRevLett.110.195502 (DOI)
Available from: 2014-02-27 Created: 2014-02-27 Last updated: 2017-12-05Bibliographically approved
Mockuté, A., Dahlqvist, M., Hultman, L., O A Persson, P. & Rosén, J. (2013). Oxygen incorporation in Ti2AlC thin films studied by electron energy loss spectroscopy and ab initio calculations. Journal of Materials Science, 48(10), 3686-3691
Open this publication in new window or tab >>Oxygen incorporation in Ti2AlC thin films studied by electron energy loss spectroscopy and ab initio calculations
2013 (English)In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 48, no 10, p. 3686-3691Article in journal (Refereed) Published
##### Abstract [en]

Substitution of C with O in hexagonal inherently nanolaminated Ti2AlC has been studied experimentally and theoretically. Ti2Al(C1−x O x ) thin films with x ≤ 0.52 are synthesized by both cathodic arc deposition with the uptake of residual gas O, and solid-state reaction between understoichiometric TiC y and Al2O3(0001) substrates. The compositional analysis is made by analytical transmission electron microscopy, including electron energy loss spectroscopy. Furthermore, predictive ab initio calculations are performed to evaluate the influence of substitutional O on the shear stress at different strains for slip on the (0001) basal plane in the [−1010] and [1−210] directions.

##### Place, publisher, year, edition, pages
Springer Verlag (Germany), 2013
##### National Category
Engineering and Technology
##### Identifiers
urn:nbn:se:liu:diva-90742 (URN)10.1007/s10853-013-7165-4 (DOI)000315518400009 ()
##### Note

Funding Agencies|European Research Council under the European Community|258509227754|Swedish Research Council (VR)||

On the day of the defence date of the Licentiate Thesis, the status of this article was Manuscript.

Available from: 2013-04-19 Created: 2013-04-05 Last updated: 2017-12-06Bibliographically approved
Petruhins, A., Ingason, A. S., Dahlqvist, M., Mockuté, A., Junaid, M., Birch, J., . . . Rosén, J. (2013). Phase stability of Crn+1GaCn MAX phases from first principles and Cr2GaC thin-film synthesis using magnetron sputtering from elemental targets. Physica Status Solidi. Rapid Research Letters, 7(11), 971-974
Open this publication in new window or tab >>Phase stability of Crn+1GaCn MAX phases from first principles and Cr2GaC thin-film synthesis using magnetron sputtering from elemental targets
2013 (English)In: Physica Status Solidi. Rapid Research Letters, ISSN 1862-6254, E-ISSN 1862-6270, Vol. 7, no 11, p. 971-974Article in journal (Refereed) Published
##### Abstract [en]

Ab-initio calculations have been used to investigate the phase stability and magnetic state of Crn+ 1GaCn MAX phase. Cr2GaC (n = 1) was predicted to be stable, with a ground state corresponding to an antiferromagnetic spin configuration. Thin-film synthesis by magnetron sputtering from elemental targets, including liquid Ga, shows the formation of Cr2GaC, previously only attained from bulk synthesis methods. The films were deposited at 650 degrees C on MgO(111) substrates. X-ray diffraction and high-resolution transmission electron microscopy show epitaxial growth of (000) MAX phase.

##### Place, publisher, year, edition, pages
Wiley-VCH Verlag, 2013
##### Keywords
MAX phases; ab-initio calculations; magnetron sputtering; epitaxial thin films
##### National Category
Engineering and Technology
##### Identifiers
urn:nbn:se:liu:diva-103307 (URN)10.1002/pssr.201308025 (DOI)000328321700009 ()
Available from: 2014-01-16 Created: 2014-01-16 Last updated: 2018-03-15

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