Logo: to the web site of Uppsala University

uu.sePublications from Uppsala University
Change search
Link to record
Permanent link

Direct link
Alternative names
Publications (10 of 113) Show all publications
Tidén, S., Abenayake, H., Löfstrand, J., Jansson, U. & Sahlberg, M. (2024). Crack reduction in laser powder bed fusion of MnAl(C) using graphene oxide coated powders. Scientific Reports, 14, Article ID 1142.
Open this publication in new window or tab >>Crack reduction in laser powder bed fusion of MnAl(C) using graphene oxide coated powders
Show others...
2024 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 14, article id 1142Article in journal (Refereed) Published
Abstract [en]

MnAl(C) is a promising candidate as a rare earth free magnet. When processing MnAl(C) in laser powder bed fusion (L-PBF) the high cooling rates can retain the high temperature epsilon-phase which can then be annealed at low temperatures to yield the ferromagnetic tau-phase. However, MnAl(C) has been shown to be difficult to print using L-PBF and the material is prone to severe cracking. In this study, we have investigated how the addition of a graphene oxide (GO) coating on the powders can affect the processability of MnAl(C) and properties of the printed parts. MnAl(C) powders were coated with 0.2 wt.% GO using a wet-chemical process. The addition of GO reduced crack formation in the printed parts, and also influenced the degree of < 001 > texture along the build direction. After printing, densities of 93% and 87% could be achieved for the reference and 0.2 wt.% GO, respectively. Furthermore, a 35% reduction of cracking was calculated from image analysis, comparing printed samples produced from coated and non-coated powders. Both powders formed mostly the e-phase but some two-phase regions with a mix of γ- and ε-phase could be observed in the as-printed parts, but seemed to be more prominent in the uncoated reference samples and could also be linked to cracks. The τ-phase together with smaller amounts of secondary phases was obtained after heat treatment at 560 degrees C for 5 min for both samples. Vibrating sample magnetometry was used to measure the magnetic properties, the reference had a remanence of 33Am2/ kg and a coercivity of 139 kA/m, and the 0.2 wt.% GO sample showed a similar remanence of 30Am2/ kg and coercivity of 130 kA/m. These results show that GO coating is a viable method to reduce detrimental cracking in L-PBF MnAl without reducing the magnetic performance of the material.

Place, publisher, year, edition, pages
Springer Nature, 2024
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-523948 (URN)10.1038/s41598-024-51283-5 (DOI)001142462100014 ()38212350 (PubMedID)
Funder
Swedish Research Council, 2022-03069
Available from: 2024-02-27 Created: 2024-02-27 Last updated: 2024-03-28Bibliographically approved
Shtender, V., Smetana, V., Crivello, J.-C. -., Kravets, A., Gondek, L., Mudring, A.-V. & Sahlberg, M. (2024). Intermetallics of 4:4:1 and 3:3:1 series in La-(Co,Ni)-M (M = Bi, Pb, Te, Sb, Sn and Ga, Al) systems and their properties. Journal of Alloys and Compounds, 982, Article ID 173767.
Open this publication in new window or tab >>Intermetallics of 4:4:1 and 3:3:1 series in La-(Co,Ni)-M (M = Bi, Pb, Te, Sb, Sn and Ga, Al) systems and their properties
Show others...
2024 (English)In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 982, article id 173767Article in journal (Refereed) Published
Abstract [en]

Two series of isostructural intermetallics have been discovered in our search for new compounds with fused honeycomb motifs, both stable at elevated temperatures (1073 K). They crystallize with orthorhombic unit cells - La4Co4M (M = Sn, Sb, Te, Pb, Bi, SG Pbam, a = 8.247-8.315(2), b = 21.913-22.137(7), c = 4.750-4.664(2) angstrom, V = 850.5-869.5(4) angstrom 3, Z = 4) and La3Ni3M (M = Al, Ga, SG Cmcm, a = 4.1790-4.2395(1), b = 10.4921-10.6426 (6), c = 13.6399-13.7616(8) angstrom, V = 606.72-612.05(7), Z = 3). The crystal structures represent interesting variations of semiregular tilings of corrugated anionic layers and predominantly cationic zigzag motifs. The La4Co4M compounds reveal a complex type of ordering with a high degree of frustration as could be expected for the Kagome ' -related lattices, while magnetic ordering in the La3Ni3M series is less evident. Electronic structure calculations have been performed for multiple compounds within both series revealing metallic character and visible local minima around the Fermi level. The bonding picture is characterized by nearly equal contributions from the anionic and the cationic components.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Intermetallics, crystal structure, electronic structure, magnetic properties
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-526081 (URN)10.1016/j.jallcom.2024.173767 (DOI)001181563000001 ()
Funder
Swedish Research CouncilSwedish Foundation for Strategic Research, EM16-0039
Available from: 2024-04-04 Created: 2024-04-04 Last updated: 2024-04-04Bibliographically approved
Clulow, R., Pramanik, P., Stolpe, A., Joshi, D. C., Mathieu, R., Henry, P. F. & Sahlberg, M. (2024). Phase Stability and Magnetic Properties of Compositionally Complex n=2 Ruddlesden-Popper Perovskites. Inorganic Chemistry, 63(15), 6616-6625
Open this publication in new window or tab >>Phase Stability and Magnetic Properties of Compositionally Complex n=2 Ruddlesden-Popper Perovskites
Show others...
2024 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 63, no 15, p. 6616-6625Article in journal (Refereed) Published
Abstract [en]

Four new compositionally complex perovskites with multiple (four or more) cations on the B site of the perovskites have been studied. The materials have the general formula La0.5Sr2.5(M)2O7−δ (M = Ti, Mn, Fe, Co, and Ni) and have been synthesized via conventional solid-state synthesis. The compounds are the first reported examples of compositionally complex n = 2 Ruddlesden–Popper perovskites. The structure and properties of the materials have been determined using powder X-ray diffraction, neutron diffraction, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and magnetometry. The materials are isostructural and adopt the archetypal I4/mmm space group with the following unit cell parameters: a ∼ 3.84 Å, and c ∼ 20.1 Å. The measured compositions from energy dispersive X-ray spectroscopy were La0.51(2)Sr2.57(7)Ti0.41(2)Mn0.41(2)Fe0.39(2)Co0.38(1)Ni0.34(1)O7−δ, La0.59(4)Sr2.29(23)Mn0.58(5)Fe0.56(6)Co0.55(6)Ni0.42(4)O7−δ, La0.54(2)Sr2.49(13)Mn0.41(2)Fe0.81(5)Co0.39(3)Ni0.36(3)O7−δ, and La0.53(4)Sr2.55(19)Mn0.67(6)Fe0.64(5)Co0.31(2)Ni0.30(3)O7−δ. No magnetic contribution is observed in the neutron diffraction data, and magnetometry indicates a spin glass transition at low temperatures.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2024
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-528188 (URN)10.1021/acs.inorgchem.3c04277 (DOI)001196512300001 ()38569100 (PubMedID)
Funder
Swedish Foundation for Strategic Research, EM 160039Swedish Research Council, 2019-00207ÅForsk (Ångpanneföreningen's Foundation for Research and Development), 22-92Olle Engkvists stiftelse, 207-0427
Available from: 2024-05-16 Created: 2024-05-16 Last updated: 2024-05-16Bibliographically approved
Pramanik, P., Clulow, R., Joshi, D. C., Stolpe, A., Berastegui, P., Sahlberg, M. & Mathieu, R. (2024). Spin glass states in multicomponent layered perovskites. Scientific Reports, 14(1), Article ID 3382.
Open this publication in new window or tab >>Spin glass states in multicomponent layered perovskites
Show others...
2024 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 14, no 1, article id 3382Article in journal (Refereed) Published
Abstract [en]

Temperature-dependent dc-magnetization and ac-susceptibility curves have been recorded for series of single and double layered Ruddlesden-Popper multicomponent perovskites with chemical formula A2BO4 and A3B2O7, respectively, with (La, Sr) on A-sites and up to 7 different cations on the B-sites (Ti, Cr, Mn, Fe, Co, Ni, Cu). The phase purity and chemical homogeneity of the compounds were investigated by X-ray diffraction and energy dispersive X-ray spectroscopy. Independently of the composition, spin glassiness is observed in both systems. Scaling analyses suggest the materials undergo spin glass phase transitions at low temperatures. Yet, qualitative differences are observed between the single-layered and double-layered systems, which are discussed in the light of the spatial dimensionality and magnetic interaction in layered oxide perovskites.

Place, publisher, year, edition, pages
Springer Nature, 2024
National Category
Condensed Matter Physics Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-526186 (URN)10.1038/s41598-024-53896-2 (DOI)001160750400068 ()38336984 (PubMedID)
Funder
Swedish Foundation for Strategic Research, EM 160039Swedish Research Council, 2019-00207Olle Engkvists stiftelse, 207-0427ÅForsk (Ångpanneföreningen's Foundation for Research and Development), 22-92Uppsala University
Available from: 2024-04-08 Created: 2024-04-08 Last updated: 2024-04-16Bibliographically approved
Pacheco, V., Skårman, B., Olsson, F., Karlsson, D., Vidarsson, H. & Sahlberg, M. (2023). Additive Manufacturing of MnAl(C)-Magnets. Alloys, 2(2), 100-109
Open this publication in new window or tab >>Additive Manufacturing of MnAl(C)-Magnets
Show others...
2023 (English)In: Alloys, E-ISSN 2674-063X, Vol. 2, no 2, p. 100-109Article in journal (Refereed) Published
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-517381 (URN)10.3390/alloys2020007 (DOI)
Funder
Swedish Foundation for Strategic Research, GSn15-0008
Available from: 2023-12-07 Created: 2023-12-07 Last updated: 2023-12-07
Ghorai, S., Vieira, R. M., Shtender, V., Delczeg-Czirjak, E. K., Herper, H. C., Björkman, T., . . . Svedlindh, P. (2023). Giant magnetocaloric effect in the (Mn,Fe)NiSi-system.
Open this publication in new window or tab >>Giant magnetocaloric effect in the (Mn,Fe)NiSi-system
Show others...
2023 (English)Manuscript (preprint) (Other academic)
Abstract [en]

The search for energy-efficient and environmentally friendly cooling technologies is a key driver for the development of magnetic refrigeration based on the magnetocaloric effect (MCE). This phenomenon arises from the interplay between magnetic and lattice degrees of freedom that is strong in certain materials, leading to a change in temperature upon application or removal of a magnetic field. Here we report on a new material, Mn1−xFexNiSi0.95Al0.05, with an exceptionally large isothermal entropy at room temperature. By combining experimental and theoretical methods we outline the microscopic mechanism behind the large MCE in this material. It is demonstrated that the competition between the Ni2In-type hexagonal phase and the MnNiSi-type orthorhombic phase, that coexist in this system, combined with the distinctly different magnetic properties of these phases, is a key parameter for the functionality of this material for magnetic cooling.

National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-525213 (URN)10.48550/arXiv.2307.00128 (DOI)
Available from: 2024-03-19 Created: 2024-03-19 Last updated: 2024-03-19
Shtender, V., Smetana, V., Crivello, J.-C., Gondek, L., Przewozznik, J., Mudring, A.-V. & Sahlberg, M. (2023). Honeycomb Constructs in the La-Ni Intermetallics: Controlling Dimensionality via p-Element Substitution. Inorganic Chemistry, 62(37), 14843-14851
Open this publication in new window or tab >>Honeycomb Constructs in the La-Ni Intermetallics: Controlling Dimensionality via p-Element Substitution
Show others...
2023 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 62, no 37, p. 14843-14851Article in journal (Refereed) Published
Abstract [en]

The new ternary compounds La15Ni13Bi5 and La9Ni8Sn5 were obtained by arc melting under argon from appropriate amounts of the elements and subsequent annealing at 800 degrees C for 2 weeks. Single-crystal X-ray diffraction reveals that they represent two new structure types: La15Ni13Bi5 crystallizes in the hexagonal space group P62m [hP33, a = 14.995(3), c = 4.3421(10) Å, V = 845.5(4) Å3, Z = 1] and La9Ni8Sn5 in P63/m [hP88, a = 23.870(15), c = 4.433(3) Å, V = 2187(3) Å3, Z = 4]. The crystal structures of both compounds are characterized by hexagonal honeycomb-based motifs formed by Ni and Sn that extend along the c axis. The building motif with its three-blade wind turbine shape is reminiscent of the organic molecule triptycene and is unprecedented in extended solids. First-principles calculations have been performed in order to analyze the electronic structure and provide insight into chemical bonding. They reveal significant electron transfer from La to Ni and the respective p-element, which supports the formation of the polyanionic Ni-p-element network. DFT calculations suggest paramagnetic-like behavior for both compounds, which was confirmed by magnetic measurements.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2023
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-514755 (URN)10.1021/acs.inorgchem.3c00502 (DOI)001064319200001 ()37676690 (PubMedID)
Funder
Swedish Research CouncilSwedish Foundation for Strategic Research, EM16-0039
Available from: 2023-10-24 Created: 2023-10-24 Last updated: 2023-10-24Bibliographically approved
Oji, U., Pacheco, V., Sahlberg, M., Backs, A., Woracek, R., Pooley, D. E., . . . Kardjilov, N. (2023). Implementation of time of flight polarized neutron imaging at IMAT-ISIS. Materials & design, 235, Article ID 112429.
Open this publication in new window or tab >>Implementation of time of flight polarized neutron imaging at IMAT-ISIS
Show others...
2023 (English)In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 235, article id 112429Article in journal (Refereed) Published
Abstract [en]

In this study, we report the first case of design and implementation of a polarized neutron imaging option on the Imaging and Materials Science & Engineering Station (IMAT). This is a significant addition to the capabilities of the station that allows the characterization of advanced magnetic materials for different engineering applications. Combining its time-of-flight feature with a polarized beam yields data that facilitate both quantitative and qualitative analysis of magnetic materials. Using the simple field of an aluminium solenoid, we perform a characterization of the new setup. In addition, we present polarized measurements of additively manufactured (AM) MnAl samples where the magnetic anisotropy due to the fabrication process has been investigated as a first scientific application of the setup. The results indicate that the anisotropy of the material can be engineered through variation of the AM fabrication parameters.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Additive manufacturing, Polarized neutron imaging, Magnetic structures
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-517378 (URN)10.1016/j.matdes.2023.112429 (DOI)001111557500001 ()
Funder
Swedish Research Council, 2022-03069Swedish Foundation for Strategic Research
Available from: 2023-12-07 Created: 2023-12-07 Last updated: 2023-12-15Bibliographically approved
Hedlund, D., Rosenqvist Larsen, S., Sahlberg, M., Svedlindh, P. & Shtender, V. (2023). Influence of Mn content on the magnetic properties of the hexagonal Mn (Co,Ge)2 phase. Scripta Materialia, 233, Article ID 115534.
Open this publication in new window or tab >>Influence of Mn content on the magnetic properties of the hexagonal Mn (Co,Ge)2 phase
Show others...
2023 (English)In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 233, article id 115534Article in journal (Refereed) Published
Abstract [en]

Herein, we report on the effect of Mn content on the magnetic properties of the hexagonal Mn(Co,Ge)2 with composition Mn36+xCo49-xGe15.This compound was previously described as Mn2Co3Ge (MgZn2-type structure), but later as Mn(Co,Ge)2 with its own structure type, all samples in this work follow the same superstructure model. Samples were synthesized by induction melting, the crystal structures were evaluated using a combination of X-ray diffraction together with scanning electron microscopy equipped and an energy dispersive X-ray spectroscopy detector. The Curie temperature (TC) is shifted towards lower temperature as the Mn content is increased. On the other hand, the spin reorientation temperature (TSRT) increases and the magnetic moment decreases as the Mn content is increased. The magnetocaloric properties were investigated for the x = 1 alloy, Mn37Co48Ge15. It was found that the isothermal entropy change is 2 J kg−1 K−1 at room temperature for an applied field of 5 T.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Permanent magnets, Intermetallic compound, Synthesis, Magnetocalloric properties, Crystal structure
National Category
Condensed Matter Physics Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-504952 (URN)10.1016/j.scriptamat.2023.115534 (DOI)001001481400001 ()
Funder
Swedish Foundation for Strategic Research, EM16-0039Swedish Research Council, 2019-00207
Available from: 2023-06-19 Created: 2023-06-19 Last updated: 2023-06-19Bibliographically approved
Ghorai, S., Cedervall, J., Clulow, R., Huang, S., Ericsson, T., Häggström, L., . . . Svedlindh, P. (2023). Site-specific atomic substitution in a giant magnetocaloric Fe2P-type system. Physical Review B, 107(10), Article ID 104409.
Open this publication in new window or tab >>Site-specific atomic substitution in a giant magnetocaloric Fe2P-type system
Show others...
2023 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 107, no 10, article id 104409Article in journal (Refereed) Published
Abstract [en]

Giant magnetocaloric (GMC) materials constitute a requirement for near room temperature magnetic refrigeration. (Fe,Mn)2(P,Si) is a GMC compound with strong magnetoelastic coupling. The main hindrance towards application of this material is a comparably large temperature hysteresis, which can be reduced by metal site substitution with a nonmagnetic element. However, the (Fe,Mn)2(P,Si) compound has two equally populated metal sites, the tetrahedrally coordinated 3f and the pyramidally coordinated 3g sites. The magnetic and magnetocaloric properties of such compounds are highly sensitive to the site specific occupancy of the magnetic atoms. Here we have attempted to study separately the effect of 3f and 3g site substitution with equal amounts of vanadium. Using formation energy calculations, the site preference of vanadium and its influence on the magnetic phase formation are described. A large difference in the isothermal entropy change (as high as 44\%) with substitution in the 3f and 3g sites is observed. The role of the lattice parameter change with temperature and the strength of the magnetoelastic coupling on the magnetic properties are highlighted.

Place, publisher, year, edition, pages
American Physical Society, 2023
National Category
Condensed Matter Physics Materials Chemistry
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-487262 (URN)10.1103/PhysRevB.107.104409 (DOI)000974419900006 ()
Funder
Swedish Foundation for Strategic Research, EM-16-0039Swedish Research Council, 2019-00645StandUpeSSENCE - An eScience CollaborationSwedish National Infrastructure for Computing (SNIC)
Available from: 2022-10-26 Created: 2022-10-26 Last updated: 2023-05-26Bibliographically approved
Projects
Application for travel funding: Solid Compounds of Transition Elements. Annecy, Frankrike. 5-10 September 2010 [2010-06401_VR]; Uppsala UniversityDevelopment of instrumentation and competence for in situ studies using thermal analysis in neutron scatering [2018-03439_VR]; Uppsala University
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-6486-5156

Search in DiVA

Show all publications