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Diao, Zhu
Publications (7 of 7) Show all publications
Zheng, Q., Zhu, G., Diao, Z., Banerjee, D. & Cahill, D. G. (2019). High Contrast Thermal Conductivity Change in Ni-Mn-In Heusler Alloys near Room Temperature. Advanced Engineering Materials, 21(5), Article ID 1801342.
Open this publication in new window or tab >>High Contrast Thermal Conductivity Change in Ni-Mn-In Heusler Alloys near Room Temperature
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2019 (English)In: Advanced Engineering Materials, ISSN 1438-1656, E-ISSN 1527-2648, Vol. 21, no 5, article id 1801342Article in journal (Refereed) Published
Abstract [en]

Materials with an abrupt transition between a low and a high thermal conductance state at a critical temperature would be useful for thermal regulation applications. Here, the authors report a high contrast reversible thermal conductivity change through the thermally-induced martensitic transition (MT) in Ni-Mn-In alloys. The authors measure the thermal conductivity of a wide temperature range 130 < T < 530 K using time-domain thermoreflectance (TDTR). The thermal conductivity of these alloys increases from ≈7.0-8.5 W m−1 K−1 to ≈11.5-13.0 W m−1 K−1 through the MT near 300 K as temperature rises, with a rate of change among the highest yet reported in solid-state materials with thermally-induced phase transitions. Based on Hall resistivity measurements, the authors further show that the change of thermal conductivity is dominated by the electronic contribution, which results from a unique carrier mobility change through the MT. Their findings highlight the interplay between the structural disorders and the thermal transport in alloys through solid-state phase transitions and open a new avenue in the search of high-performance materials for thermal regulation. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Place, publisher, year, edition, pages
Weinheim: Wiley-VCH Verlagsgesellschaft, 2019
Keywords
Hall mobility, Heusler alloys, martensitic transition, thermal conductivity regulation, time-domain thermoreflectanc
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hh:diva-41456 (URN)10.1002/adem.201801342 (DOI)000473099800003 ()2-s2.0-85066113113 (Scopus ID)
Funder
Swedish Research Council, 2015-00585
Note

Other funders: Toyota Motor North America (TMNA) & National Science Foundation MRSEC program under NSF (DMR-1720633) & European Union (EU) (INCA 600398)

Available from: 2020-01-31 Created: 2020-01-31 Last updated: 2020-03-23Bibliographically approved
Smylie, M. P., Willa, K., Bao, J.-K. -., Ryan, K., Islam, Z., Claus, H., . . . Welp, U. (2018). Anisotropic superconductivity and magnetism in single-crystal RbEuFe4As4. Physical Review B, 98(10), Article ID 104503.
Open this publication in new window or tab >>Anisotropic superconductivity and magnetism in single-crystal RbEuFe4As4
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2018 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 98, no 10, article id 104503Article in journal (Refereed) Published
Abstract [en]

We investigate the anisotropic superconducting and magnetic properties of single-crystal RbEuFe4As4 using magnetotransport and magnetization measurements. We determine a magnetic ordering temperature of the Eu moments of Tm=15K and a superconducting transition temperature of Tc=36.8K. The superconducting phase diagram is characterized by high upper critical field slopes of -70 and -42 kG/K for in-plane and out-of-plane fields, respectively, and a surprisingly low superconducting anisotropy of Γ=1.7. Ginzburg-Landau parameters of κc∌67 and κab∌108 indicate extreme type-II behavior. These superconducting properties are in line with those commonly seen in optimally doped Fe-based superconductors. In contrast, Eu magnetism is quasi-two dimensional (2D), as evidenced by highly anisotropic in-plane and out-of-plane exchange constants of 0.6 K and <0.04 K. A consequence of the quasi-2D nature of the Eu magnetism are strong magnetic fluctuation effects, a large suppression of the magnetic ordering temperature as compared to the Curie-Weiss temperature, and a kinklike anomaly in the specific heat devoid of any singularity. Magnetization curves reveal a clear magnetic easy-plane anisotropy with in-plane and out-of-plane saturation fields of 2 and 4 kG. © 2018 American Physical Society.

Place, publisher, year, edition, pages
College Park: American Physical Society, 2018
National Category
Condensed Matter Physics Inorganic Chemistry
Identifiers
urn:nbn:se:hh:diva-38701 (URN)10.1103/PhysRevB.98.104503 (DOI)000443672100005 ()2-s2.0-85053136770 (Scopus ID)
Funder
Swedish Research Council, 2015-00585EU, Horizon 2020, 2016-04516EU, Horizon 2020, INCA 600398Swedish Research Council, 2016-04516
Available from: 2019-01-08 Created: 2019-01-08 Last updated: 2022-06-07Bibliographically approved
Campanini, D., Diao, Z. & Rydh, A. (2018). Raising the superconducting Tc of gallium: In situ characterization of the transformation of α -Ga into β -Ga. Physical Review B, 97(18), Article ID 184517.
Open this publication in new window or tab >>Raising the superconducting Tc of gallium: In situ characterization of the transformation of α -Ga into β -Ga
2018 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 97, no 18, article id 184517Article in journal (Refereed) Published
Abstract [en]

Gallium (Ga) displays several metastable phases. Superconductivity is strongly enhanced in the metastable β-Ga with a critical temperature Tc=6.04(5)K, while stable α-Ga has a much lower Tc<1.2K. Here we use a membrane-based nanocalorimeter to initiate the transition from α-Ga to β-Ga on demand, as well as study the specific heat of the two phases on one and the same sample. The in situ transformation is initiated by bringing the temperature to about 10K above the melting temperature of α-Ga. After such treatment, the liquid supercools down to 232K, where β-Ga solidifies. We find that β-Ga is a strong-coupling type-I superconductor with Δ(0)/kBTc=2.00(5) and a Sommerfeld coefficient γn=1.53(4)mJ/molK2, 2.55 times higher than that in the α phase. The results allow a detailed comparison of fundamental thermodynamic properties between the two phases. © 2018 American Physical Society.

Place, publisher, year, edition, pages
American Physical Society, 2018
National Category
Metallurgy and Metallic Materials Other Physics Topics
Identifiers
urn:nbn:se:hh:diva-38708 (URN)10.1103/PhysRevB.97.184517 (DOI)000433287200004 ()2-s2.0-85048246191 (Scopus ID)
Available from: 2019-01-08 Created: 2019-01-08 Last updated: 2022-06-07Bibliographically approved
Zheng, Q., Murray, S. E., Diao, Z., Bhutani, A., Shoemaker, D. P. & Cahill, D. G. (2018). Thermal transport through the magnetic martensitic transition in MnxM Ge(M = Co, Ni). Physical Review Materials, 2(7), Article ID 075401.
Open this publication in new window or tab >>Thermal transport through the magnetic martensitic transition in MnxGe(M = Co, Ni)
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2018 (English)In: Physical Review Materials, E-ISSN 2475-9953, Vol. 2, no 7, article id 075401Article in journal (Refereed) Published
Abstract [en]

We report on changes in the thermal conductivity of solid-state synthesized MnxGe (M = Co, Ni, 0.98 < x < 1.02) alloys through their temperature-induced martensitic structural transition. The thermal conductivity is measured by time-domain thermoreflectance. Mn1.014 NiGe exhibits an increase in thermal conductivity from 11 to 15.5 W m-1 K-1 from approximately 575 to 625 K, and Mn1.007 CoGe exhibits an increase in thermal conductivity from 7 to 8.5 W m-1 K-1 from 500 to 550 K. In MnxNiGe, the transition temperature and the magnitude of the change in thermal conductivity are strongly dependent on the alloy composition. Our study advances the fundamental understanding of the thermal transport properties in the MnxGe(M = Co, Ni) family of alloys and opens a new direction in the search for solid-state phase transition materials with potential applications as thermal regulators. © 2018 American Physical Society

Place, publisher, year, edition, pages
College Park: American Physical Society, 2018
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:hh:diva-41488 (URN)10.1103/PhysRevMaterials.2.075401 (DOI)000436946800003 ()2-s2.0-85059636119 (Scopus ID)
Available from: 2020-02-03 Created: 2020-02-03 Last updated: 2020-05-11Bibliographically approved
Diao, Z., Sauer, V. T. K. & Hiebert, W. K. (2017). Integrated On-Chip Nano-Optomechanical Systems. International Journal of High Speed Electronics and Systems, 26(1-2), Article ID 1740005.
Open this publication in new window or tab >>Integrated On-Chip Nano-Optomechanical Systems
2017 (English)In: International Journal of High Speed Electronics and Systems, ISSN 0129-1564, Vol. 26, no 1-2, article id 1740005Article in journal (Refereed) Published
Abstract [en]

Recent developments in integrated on-chip nano-optomechanical systems are reviewed. Silicon-based nano-optomechanical devices are fabricated by a two-step process, where the first step is a foundry-enabled photonic circuits patterning and the second step involves in-house mechanical device release. We show theoretically that the enhanced responsivity of near-field optical transduction of mechanical displacement in on-chip nano-optomechanical systems originates from the finesse of the optical cavity to which the mechanical device couples. An enhancement in responsivity of more than two orders of magnitude has been observed when compared side-by-side with free-space interferometry readout. We further demonstrate two approaches to facilitate large-scale device integration, namely, wavelength-division multiplexing and frequency-division multiplexing. They are capable of significantly simplifying the design complexity for addressing individual nano-optomechanical devices embedded in a large array. © 2017 World Scientific Publishing Company.

Place, publisher, year, edition, pages
Singapore: World Scientific Publishing Co. Pte Ltd, 2017
Keywords
Nanomechanical resonators, Nano-optomechanical systems, Nanophotonics
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:hh:diva-33032 (URN)10.1142/S0129156417400055 (DOI)2-s2.0-85013339684 (Scopus ID)
Available from: 2017-01-12 Created: 2017-01-12 Last updated: 2022-06-07Bibliographically approved
Willa, K., Diao, Z., Campanini, D., Welp, U., Divan, R., Hudl, M., . . . Rydh, A. (2017). Nanocalorimeter platform for in situ specific heat measurements and x-ray diffraction at low temperature. Review of Scientific Instruments, 88(12), Article ID 125108.
Open this publication in new window or tab >>Nanocalorimeter platform for in situ specific heat measurements and x-ray diffraction at low temperature
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2017 (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 88, no 12, article id 125108Article in journal (Refereed) Published
Abstract [en]

Recent advances in electronics and nanofabrication have enabled membrane-based nanocalorimetry for measurements of the specific heat of microgram-sized samples. We have integrated a nanocalorimeter platform into a 4.5 T split-pair vertical-field magnet to allow for the simultaneous measurement of the specific heat and x-ray scattering in magnetic fields and at temperatures as low as 4 K. This multi-modal approach empowers researchers to directly correlate scattering experiments with insights from thermodynamic properties including structural, electronic, orbital, and magnetic phase transitions. The use of a nanocalorimeter sample platform enables numerous technical advantages: precise measurement and control of the sample temperature, quantification of beam heating effects, fast and precise positioning of the sample in the x-ray beam, and fast acquisition of x-ray scans over a wide temperature range without the need for time-consuming re-centering and re-alignment. Furthermore, on an YBa2Cu3O7−δ crystal and a copper foil, we demonstrate a novel approach to x-ray absorption spectroscopy by monitoring the change in sample temperature as a function of incident photon energy. Finally, we illustrate the new insights that can be gained from in situ structural and thermodynamic measurements by investigating the superheated state occurring at the first-order magneto-elastic phase transition of Fe2P, a material that is of interest for magnetocaloric applications. © 2017 Author(s).

Place, publisher, year, edition, pages
Melville, NY: American Institute of Physics (AIP), 2017
National Category
Other Physics Topics
Identifiers
urn:nbn:se:hh:diva-36623 (URN)10.1063/1.5016592 (DOI)000418956500066 ()2-s2.0-85038447443 (Scopus ID)
Funder
Swedish Research Council, 2015-00585Swedish Research Council, 2016-04516The Royal Swedish Academy of Sciences
Note

Funding: U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. The calorimeter integration was supported through the APS visiting scientist program (A.R.). Use of the Center for Nanoscale Materials and Advanced Photon Source, Office of Science user facilities, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. K.W. acknowledges support from the Swiss National Science Foundation through an Early Postdoc Mobility fellowship. Z.D. acknowledges support from the Swedish Research Council (VR) under Grant No. 2015-00585, co-funded by Marie Sklodowska-Curie Actions (Project No. INCA 600398). D.C. acknowledges support from the Royal Swedish Academy of Sciences. A.R. acknowledges support from the Swedish Research Council (VR) under Grant No. 2016-04516.

Available from: 2018-04-17 Created: 2018-04-17 Last updated: 2022-06-07Bibliographically approved
Sauer, V. T. K., Diao, Z., Westwood-Bachman, J. N., Freeman, M. R. & Hiebert, W. K. (2017). Single laser modulated drive and detection of a nano-optomechanical cantilever. AIP Advances, 7(1), Article ID 015115.
Open this publication in new window or tab >>Single laser modulated drive and detection of a nano-optomechanical cantilever
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2017 (English)In: AIP Advances, E-ISSN 2158-3226, Vol. 7, no 1, article id 015115Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Melville, NY: American Institute of Physics (AIP), 2017
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:hh:diva-33034 (URN)10.1063/1.4975347 (DOI)000395789900057 ()
Available from: 2017-01-12 Created: 2017-01-12 Last updated: 2023-03-28Bibliographically approved
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