@article{allen-perry_straka_keith_han_reynolds_gautam_autrey_2021, title={Tuning the Magnetic Properties of Two-Dimensional MXenes by Chemical Etching}, volume={14}, ISSN={["1996-1944"]}, DOI={10.3390/ma14030694}, abstractNote={Two-dimensional materials based on transition metal carbides have been intensively studied due to their unique properties including metallic conductivity, hydrophilicity and structural diversity and have shown a great potential in several applications, for example, energy storage, sensing and optoelectronics. While MXenes based on magnetic transition elements show interesting magnetic properties, not much is known about the magnetic properties of titanium-based MXenes. Here, we measured the magnetic properties of Ti3C2Tx MXenes synthesized by different chemical etching conditions such as etching temperature and time. Our magnetic measurements were performed in a superconducting quantum interference device (SQUID) vibrating sample. These data suggest that there is a paramagnetic-antiferromagnetic (PM-AFM) phase transition and the transition temperature depends on the synthesis procedure of MXenes. Our observation indicates that the magnetic properties of these MXenes can be tuned by the extent of chemical etching, which can be beneficial for the design of MXenes-based spintronic devices.}, number={3}, journal={MATERIALS}, author={Allen-Perry, Kemryn and Straka, Weston and Keith, Danielle and Han, Shubo and Reynolds, Lewis and Gautam, Bhoj and Autrey, Daniel E.}, year={2021}, month={Feb} }
 @article{straka_amoah_schwartz_2017, title={Densification of thoria through flash sintering}, volume={7}, ISSN={["2159-6867"]}, DOI={10.1557/mrc.2017.70}, abstractNote={Thorium dioxide (thoria, ThO_2) is used in refractory applications and as nuclear fuel. Its melting temperature, the highest of any binary oxide, makes it a difficult system to process. Here we report on the effects of flash sintering on the densification of thoria. We found 95% of theoretical density is obtained at ~950 °C (~30% of the melting temperature) with an electric field of 800 V/cm. Variation in power density had a minimal effect on the densification. Scanning electron microscopy images show the effects of flash sintering on grain size as a function of electric field.}, number={3}, journal={MRS COMMUNICATIONS}, author={Straka, W. and Amoah, S. and Schwartz, J.}, year={2017}, month={Sep}, pages={677–682} }
 @article{ishmael_rogers_hunte_naderi_roach_straka_schwartz_2015, title={Current Density and Quench Behavior of MgB2/Ga Composite Wires}, volume={25}, ISSN={["1558-2515"]}, DOI={10.1109/tasc.2015.2483597}, abstractNote={Magnesium diboride (MgB 2) is a promising superconductor for many technical applications. Sufficient current densities at required magnetic fields, moderate operational temperature, low raw materials' cost, and an economical manufacturing process have enabled commercial development of MgB 2 wires. Reacted MgB 2, however, is brittle, and applications involving coils and windings with small bend radii are therefore difficult to implement. Furthermore, improvements in the critical current density are needed to expand the range of potential applications. Here, we report on the electrical behavior of novel MgB 2/Ga composite wires produced such that the proximity effect enhances connectivity, allowing the high-temperature anneal typically required for in situ and ex situ MgB 2 wires to be eliminated. Elimination of the high-temperature anneal simplifies MgB 2 manufacturing and has the potential to create a wire that is more tolerant of bending. Here, we present critical current density and quench propagation results for MgB 2/Ga composite wires sheathed in Cu.}, number={6}, journal={IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY}, author={Ishmael, Sasha A. and Rogers, Samuel and Hunte, Frank and Naderi, Golsa and Roach, Christian and Straka, Weston and Schwartz, Justin}, year={2015}, month={Dec} }
 @article{seifikar_rawdanowicz_straka_quintero_bassiri-gharb_schwartz_2014, title={Structural and magnetic properties of sol-gel derived NiFe2O4 thin films on silicon substrates}, volume={361}, ISSN={["1873-4766"]}, DOI={10.1016/j.jmmm.2014.03.004}, abstractNote={Spinel NiFe2O4 thin films are derived via chemical solution deposition on silicon substrates. The films show a granular microstructure with surface roughness of less than 3 nm. The effects of varying the pyrolysis and annealing conditions on the microstructure and resulting magnetic properties have been studied. Microstructural studies confirm the formation of randomly oriented, phase-pure spinel nickel ferrite for pyrolysis at 100 °C to 500 °C and crystallization at 650 °C to 900 °C for 10 to 30 min. It is shown that the pyrolysis temperature does not affect the microstructure and the resulting magnetic properties, while increasing annealing temperature results in increased grain size and saturation magnetization. Transmission electron microcopy shows that no intermediate or secondary phase has formed at the interface even at annealing temperature as high as 900 °C.}, journal={JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS}, author={Seifikar, Safoura and Rawdanowicz, Thomas and Straka, Weston and Quintero, Christopher and Bassiri-Gharb, Nazanin and Schwartz, Justin}, year={2014}, month={Jun}, pages={255–261} }
 @article{ishmael_slomski_luo_white_hunt_mandzy_muth_nesbit_paskova_straka_et al._2014, title={Thermal conductivity and dielectric properties of a TiO2-based electrical insulator for use with high temperature superconductor-based magnets}, volume={27}, ISSN={["1361-6668"]}, DOI={10.1088/0953-2048/27/9/095018}, abstractNote={Quench protection is a remaining challenge impeding the implementation of high temperature superconductor (HTS)-based magnet applications. This is due primarily to the slow normal zone propagation velocity (NZPV) observed in Bi2Sr2CaCu2OX (Bi2212) and (RE)Ba2Cu3O7 − x (REBCO) systems. Recent computational and experimental findings reveal significant improvements in turn-to-turn NZPV, resulting in a magnet that is more stable and easier to protect through three-dimensional normal zone growth (Phillips M 2009; Ishmael S et al 2013 IEEE Trans. Appl. Supercond. 23 7201311). These improvements are achieved by replacing conventional insulation materials, such as Kapton and mullite braid, with a thin, thermally conducting, electrically-insulating ceramic oxide coating. This paper reports on the temperature-dependent thermal properties, electrical breakdown limits and microstructural characteristics of a titanium oxide (TiO2) insulation and a doped-TiO2-based proprietary insulation (doped-TiO2) shown previously to enhance quench behavior (Ishmael S et al 2013 IEEE Trans. Appl. Supercond. 23 7201311). Breakdown voltages at 77 K ranging from ∼1.5 kV to over 5 kV are reported. At 4.2 K, the TiO2 increases the thermal conductivity of polyimide by about a factor of 10. With the addition of a dopant, thermal conductivity is increased by an additional 13%, and a high temperature heat treatment increases it by nearly an additional 100%. Similar increases are observed at 77 K and room temperature. These results are understood in the context of the various microstructures observed.}, number={9}, journal={SUPERCONDUCTOR SCIENCE & TECHNOLOGY}, author={Ishmael, S. A. and Slomski, M. and Luo, H. and White, M. and Hunt, A. and Mandzy, N. and Muth, J. F. and Nesbit, R. and Paskova, T. and Straka, W. and et al.}, year={2014}, month={Sep} }