14 research outputs found
Ru doping induced spin frustration and enhancement of the room-temperature anomalous Hall effect in La2/3Sr1/3MnO3 films
In transition-metal-oxide heterostructures, the anomalous Hall effect (AHE)
is a powerful tool for detecting the magnetic state and revealing intriguing
interfacial magnetic orderings. However, achieving a larger AHE at room
temperature in oxide heterostructures is still challenging due to the dilemma
of mutually strong spin-orbit coupling and magnetic exchange interactions.
Here, we exploit the Ru doping-enhanced AHE in LSMRO epitaxial films. As the
B-site Ru doping level increases up to 20 percent, the anomalous Hall
resistivity at room temperature can be enhanced from nOhmcm to uOhmcm scale. Ru
doping leads to strong competition between ferromagnetic double-exchange
interaction and antiferromagnetic super-exchange interaction. The resultant
spin frustration and spin-glass state facilitate a strong skew-scattering
process, thus significantly enhancing the extrinsic AHE. Our findings could
pave a feasible approach for boosting the controllability and reliability of
oxide-based spintronic devices
Super-tetragonal Sr4Al2O7: a versatile sacrificial layer for high-integrity freestanding oxide membranes
Releasing the epitaxial oxide heterostructures from substrate constraints
leads to the emergence of various correlated electronic phases and paves the
way for integrations with advanced semiconductor technologies. Identifying a
suitable water-soluble sacrificial layer, compatible with the high-quality
epitaxial growth of oxide heterostructures, is currently the key to the
development of large-scale freestanding oxide membranes. In this study, we
unveil the super-tetragonal Sr4Al2O7 (SAOT) as a promising water-soluble
sacrificial layer. The distinct low-symmetric crystal structure of SAOT enables
a superior capability to sustain epitaxial strain, thus allowing for broad
tunability in lattice constants. The resultant structural coherency and
defect-free interface in perovskite ABO3/SAOT heterostructures effectively
restrain crack formations during the water-assisted release of freestanding
oxide membranes. For a variety of non-ferroelectric oxide membranes, the
crack-free areas can span up to a few millimeters in length scale. These
compelling features, combined with the inherent high-water solubility, make
SAOT a versatile and feasible sacrificial layer for producing high-quality
freestanding oxide membranes, thereby boosting their potential for innovative
oxide electronics and flexible device designs.Comment: 5 figures and SI, it is the second version of this manuscrip
Phase transition in bulk single crystals and thin films of VO2 by nanoscale infrared spectroscopy and imaging
We have systematically studied a variety of vanadium dioxide (VO2) crystalline forms, including bulk single crystals and oriented thin films, using infrared (IR) near-field spectroscopic imaging techniques. By measuring the IR spectroscopic responses of electrons and phonons in VO2 with sub-grain-size spatial resolution (âŒ20nm), we show that epitaxial strain in VO2 thin films not only triggers spontaneous local phase separations, but also leads to intermediate electronic and lattice states that are intrinsically different from those found in bulk. Generalized rules of strain- and symmetry-dependent mesoscopic phase inhomogeneity are also discussed. These results set the stage for a comprehensive understanding of complex energy landscapes that may not be readily determined by macroscopic approaches
SSRP1 promotes colorectal cancer progression and is negatively regulated by miRâ28â5p
In this study, microarray data analysis, realâtime quantitative PCR and immunohistochemistry were used to detect the expression levels of SSRP1 in colorectal cancer (CRC) tissue and in corresponding normal tissue. The association between structureâspecific recognition protein 1 (SSRP1) expression and patient prognosis was examined by KaplanâMeier analysis. SSRP1 was knocked down and overexpressed in CRC cell lines, and its effects on proliferation, cell cycling, migration, invasion, cellular energy metabolism, apoptosis, chemotherapeutic drug sensitivity and cell phenotypeârelated molecules were assessed. The growth of xenograft tumours in nude mice was also assessed. MiRNAs that potentially targeted SSRP1 were determined by bioinformatic analysis, Western blotting and luciferase reporter assays. We showed that SSRP1 mRNA levels were significantly increased in CRC tissue. We also confirmed that this upregulation was related to the terminal tumour stage in CRC patients, and high expression levels of SSRP1 predicted shorter diseaseâfree survival and faster relapse. We also found that SSRP1 modulated proliferation, metastasis, cellular energy metabolism and the epithelialâmesenchymal transition in CRC. Furthermore, SSRP1 induced apoptosis and SSRP1 knockdown augmented the sensitivity of CRC cells to 5âfluorouracil and cisplatin. Moreover, we explored the molecular mechanisms accounting for the dysregulation of SSRP1 in CRC and identified microRNAâ28â5p (miRâ28â5p) as a direct upstream regulator of SSRP1. We concluded that SSRP1 promotes CRC progression and is negatively regulated by miRâ28â5p.Published versio
Strain-Driven Dzyaloshinskii-Moriya Interaction for Room-Temperature Magnetic Skyrmions
Dzyaloshinskii-Moriya interaction in magnets, which is usually derived from inversion symmetry breaking at interfaces or in noncentrosymmetric crystals, plays a vital role in chiral spintronics. Here we report that an emergent Dzyaloshinskii-Moriya interaction can be achieved in a centrosymmetric material, La0.67Sr0.33MnO3, by a graded strain. This strain-driven Dzyaloshinskii-Moriya interaction not only exhibits distinctive two coexisting nonreciprocities of spin-wave propagation in one system, but also brings about a robust room-temperature magnetic skyrmion lattice as well as a spiral lattice at zero magnetic field. Our results demonstrate the feasibility of investigating chiral spintronics in a large category of centrosymmetric magnetic materials