Welcome to the Zink Research Lab in the Department of Physics and Astronomy at the University of Denver!
Our work is in experimental condensed matter physics, exploring themes of order and disorder in novel materials and small structures primarily through studies of thermal, electronic, thermoelectric, and spin transport. Many of these measurements are enabled by micro- and nanofabrication of specialized thermal isolation platforms and other structures that enable accurate control and measurement of thermal gradients. Applications of our work range from nanoscience to nonproliferation.
Please explore this page for more information on who we are and what we do! The menus above describe our current projects, people, equipment, publications, etc... Note also that this page is, and probably always will be in some sense, under construction...
Latest News:
May, 2024: BLZ to attend 13th International Workshop on Spin Caloritronics in Beijing
Barry will travel to China to present an invited talk on magnon drag
effects in metallic ferromagnet thin films with low damping. Check out the
slides here, if
interested.
May, 2024: Congratulations to PhD
graduates Sam Bleser, Matthew Natale, and Leo Hernandez!
These three fantastic students all finished within a month of one another. We wish them the best in new postdoc positions at the University of Utah, CU Boulder/NIST, and UT Austin! We will miss you...
Nov, 2023: Zink Group attends MMM 2023 in Dallas!
Three PhD students from the group, Matt Natale, Sam Bleser, and Leo Hernandez gave talks or posters (and tried to find jobs!) at a fabulous conference (perhaps a somewhat biased opinion) in Dallas.
June, 2023: Congratulations to PhD
graduate Mike Roos!
After a successful PhD defense earlier this spring, we are proud and
excited to see Mike become the eighth PhD graduate from the group.
November, 2022: Zink Group attends MMM
2022 in Minneapolis!
Three PhD students from the group, Mike Roos, Matt Natale, and Sam Bleser, presented talks or posters at our first "real" conference in many years.
November, 2022: "Thermal effects in
spintronic materials and devices: An experimentalist’s guide,
published in Journal of Applied
Physics.
This paper overviews basic effects and key points of understanding for
what happens when spintronics gets hot. Published as part of a
special issue of Journal of Magnetism and Magnetic Materials
that honors Prof. Chia-Ling Chien of Johns Hopkins. Happy to be a
part of this! Check it out here.
March, 2022: Paper on spin-charge conversion in thermally evaporated Cr, and potential role of antiferromagnetism, published in Journal of Applied Physics.
Collaborative work using the longitudinal spin Seebeck effect (LSSE) to
probe spin-to-charge conversion in thermally evaporated chromium thin
films, which shows significant spin conversion voltage for certain
thickness, and may evolve with strain. Thanks to lead author, Sam
Bleser, and our local collaborators in Xin Fan's lab! Check it out here.
March, 2022: Paper on antiferromagnetic
coupling of a mixed-garnet interface layer that forms at the YIG/GGG
interface published in Physical
Review Materials.
Results from a wonderful, long-running collaboration between our group,
the NIST Center for Neutron Research, and Colorado State University,
featuring heroic efforts by lead author Mike Roos to do SQUID magnetometry
on the very challenging huge paramagnetic background of GGG. Check
it out here.
November, 2021: Paper on non-electronic
contributions to thermal conductivity in a low-damping metallic
ferromagnet published as a letter in Physical
Review Materials
Exciting results on thermal conductivity in Co-Fe alloys, where the low damping promotes long-lived spin dynamics, and non-electronic contributions to thermal conductivity (probed with our unique micromachined thermal isolation platorms). Thanks to first-author Matt Natale, our NIST Boulder collaborators (Justin Shaw, Hans Nembach and team) and all who contributed. Check it out here!
October, 2021: Prof. Zink gives (virtual)
invited talk at the APS Four Corners Section meeting
Thanks to the organizers at CU Boulder for the chance to talk on some
interesting recent thermal conductivity results!
September, 2021: Zink Group at FRAMS 2021, hosted by CSU
We masked-up and headed to our first in-person conference for a long time,
complete with in-person poster sessions. It was great to see friends
and colleagues old and new, in Fort Collins.
November, 2020: PhD students Sam Bleser, Leo Hernandez give virtual contributed talks at MMM2020
Both projects are collaborations with our colleagues in Prof. Xin Fan's group. One on large spin conversion in thermally evaporated chromium films, and the second comparing the anomalous Hall effect and SQUID magnetometry on synthetic ferrimagnets.
October, 2020: Paper on very unusual phonon heat transport in carbon nanotube thermoelectrics published in Advanced Electronic Materials
More fruit of our collaboration with NREL (thanks Andrew Ferguson and
Jeffery Blackburn). A certain preparation of semiconducting carbon
nanotubes shows nearly zero phonon thermal conductivity at modestly
reduced temperature. Check it out: here!
March, 2020: COVID, cancelled meetings,
and quarantines...
DU's response is amazing, but the world is weird.
Feb, 2020: Paper on absolute and relative Seebeck effect in thin films and nanostructures published in Journal of Applied Physics
This paper is the first in a long list of things we want to finally finish
in 2020. This shows one way to extract the absolute Seebeck
coefficient from thermoelectric measurements made with micro- and
nanomachined structures like our silicon-nitride platforms. Thanks
to all who contributed, and the JAP editors for making it an "Editor's
Pick!" Check it out here.
Nov, 2019: Zink Group presents three
posters and a contributed talk at MMM, in Las Vegas NV
Prof. Zink also served as one of the Program Committee Chairs. Fun, but intense! One highlight was the glow-in-the-dark KISS mini golf at the Student Reception.
Sept, 2019: Rachel Bennet and Alex
Hojem's work on membrane-suspended non-local spin valves published in Physical
Review B
This was a fun and interesting project where we used extreme measures to apply large in-plane thermal gradients to the ferromagnetic nanowires in a non-local spin valve, producing large and quantifiable anomalous Nernst effect contributions. Check it out here.
Sept, 2019: Prof. Xin Fan's group
publishes work on Anomalous Spin Orbit Torques in Nature
Nanotech
With some minor contributions from us...check it out here.
May-June, 2019: New sample prep clean
room installed, and limited He recovery from DU Chem & BioChem NMR
underway...
Leo Hernandez and friends completed installation for a new, cleaner home for our bonder and sample storage. We have also devised a very home-grown solution to recovering He gas from the NMR across the street...
Mar-Apr 2019: The Zink Lab is excited to host Prof. Yayoi Takamura (UC Davis Mat. Sci.) for part of her Sabbatical
We enjoyed discussions and talks with Yayoi,
as well as a lovely group party with some fine golf swings on display...
Dec, 2018: (slowly) Getting back to business....
With a huge amount of effort from the PhD student crew, we are slowly getting things back up and running. Not at full speed yet...
Fall 2018: Umm...that's not ideal...
Unfortunately, lab had to entirely shut down for asbestos abatement. Will return asap, and at least somewhat better than before...
May, 2018: Latest work on thermoelectric
effects in metallic ferromagnets published in Journal
of Physics D: Applied Physics.
Our (probably) final work, again led by Devin Wesenberg, clarifying that
spin currents are not generated by in-plane thermal gradients on mm-scales
in metallic ferromagnets. The result includes a unique, direct
comparison of the planar Nernst effect and planar Hall effect for a single
thin-film sample. This suggests a possible violation of the Mott
relation of these transverse thermoelectric effects. Find it here.
Dec, 2017: Congratulations to Dr. Devin Wesenberg on a very successful Ph.D. defense, and good luck at Lam!
Oct, 2017: Our surprising results on
nonlocal spin transport in disordered YIG published in Nature
Physics
Experiments led by Devin Wesenberg on material grown by Mingzhong Wu's
group at CSU, with contributions from our colleague Davor Balzar: https://www.nature.com/articles/nphys4175
Oct, 2017: Delivery and installation of
our "new" SQUID magnetometer!
Adding critical tools for understanding magnetism in materials, including disordered systems for spin transport.
Sept, 2017: Paper on n- and p-type
thermoelectric carbon nanotube films (in collaboration with NREL)
published in Energy & Environmental Sciences
Remarkable properties of highly tuned materials prepared by NREL, with thermal conductivity measured here. Check it out...here.
Aug, 2017: Prof. Fan and Zink's Groups
Host the 4th Annual Front Range Magnetics Symposium (FRAMS) at DU.
We enjoyed hosting our colleagues from CSU, CU Boulder, UCCS, U. Wyoming, and NIST for an exciting day of talks, posters, and discussions. Thanks to all who contributed!
Aug, 2017: Delivery and installation of our liquid helium recycling facility!
Thanks for NSF for supporting this critical infrastructure.
Nov, 2016: Zink group members (BLZ, Rachel Bennet, and Alex Hojem) attended MMM in New Orleans, LA.
Participation in an epic floating welcome banquet was a highlight!
July 21, 2016: Thermal spin injection PRB published, and highlighted as an Editor's Suggestion!
June 30, 2016: Alex's Hojem's work on
thermal spin injection in non-local spin valves accepted by Phys.
Rev. B!
June 26-30, 2016: DU Physics makes a
strong showing at Magnetic North V, at UC Colorado Springs. Many
congratulations to Devin Wesenberg for winning best poster!
May 2, 2016: Paper on spin transport through
magnetic oxides and large spin Hall angle in impure gold films,
collaboration with the University
of Minnesota and the Walther
Meissner Institute published in Physical
Review B!
April 4, 2016: Paper on improved
thermoelectric properties in carbon nanotube/polymer hybrid films,
collaboration with NREL and KAIST published online in Nature
Energy! Also discussed in a "News & Views"
article, "Thermoelectrics:
Carbon nanotubes get high."
Mar. 20-23: Prof. Zink participates in
"MXLS-2016, New Opportunities for Magnetic Dynamics and Materials,"
workshop in Vail, CO. Even makes it back to Denver despite the
Blizzard of 2016.
Mar. 16, 2016: Prof. Zink presents results
on tunable thermoelectric properties of Carbon Nanotube thin films from
DU/MSU/NREL/KAIST collaboration at APS March Meeting, Baltimore, MD.
Mar, 2016: Zink Group welcomes PhD
student Rachel Bennet!
Feb. 2016: Revived a group web page!
Jan. 11-15, 2016: Zink group presents two posters and a contributed talk at the 2016 Joint MMM/Intermag.
Dec. 8, 2015: PRB paper on thermal conductivity in Py, Al, Co, Cu thin films published online!(http://journals.aps.org/prb/abstract/10.1103/PhysRevB.92.214410)
Sept. 22, 2015: Alex Hojem selected as Best Poster Awardee at the first Front Range Advanced Magnetics Symposium (FRAMS) for his contribution on thermal effects in non local spin valves. Congratulations Alex!
Mar-June 2015: Prof. Zink in residence at
NIST Boulder Quantum Devices Group as part of sabbatical.
Jan-Feb 2015: Prof. Zink in residence at University of Minnesota CEMS Department as George T. Piercy Distinguished Visiting Professor
Nov.
2014: Zink Group members present two posters at MMM 2014, Honolulu,
Hawaii
