Using complementary experiments we show that the room temperature ferromagnetism observed in anatase Co:TiO(2) films is not carrier mediated, but coexists with the dielectric state. TEM and x-ray absorption spectroscopy reveal a solid solution of Co in anatase, where Co is not metallic but in the +2 state substituting for Ti. Measurements at 300 K yield a M(S) of 1.1 mu(B)/Co atom, while all films are highly insulating. The evidence of intrinsic ferromagnetism in the dielectric ground state of Co:TiO(2) leads to new considerations for the origin of ferromagnetism in transition metal doped oxides.

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We experimentally investigate the room temperature ferromagnetism observed in insulating Co doped anatase TiO2 thin films grown by sputter deposition. The Co was uniformly incorporated in the lattice as Co(II) with no evidence of Co metal. A series of annealing treatments were carried out to optimize the ferromagnetic ordering and a saturation moment of 1.1μB∕Co atom at 300 K was obtained with UHV annealing at 450 °C. Both as-deposited and annealed films were highly insulating at room temperature. Results show that the ferromagnetism is strongly dependent on the number and distribution of oxygen vacancies in the Co:TiO2 lattice.

The motion of twin boundaries in Ni-Mn-Ga ferromagnetic shape memory alloy (FSMA) particles embedded in a polymer matrix has been proposed as an effective mechanism for the dissipation of vibration energy. Indirect evidence of the motion of these boundaries through vibrating sample magnetometer measurements on FSMA/polyurethane matrix composite is shown. r

The fungal members of Carbohydrate Esterase family 1 (CE1) from the CAZy database include both acetyl xylan esterases (AXEs) and feruloyl esterases (FAEs). AXEs and FAEs are essential auxiliary enzymes to unlock the full potential of feedstock. They are being used in many biotechnology applications including food and feed, pulp and paper, and biomass valorization. AXEs catalyze the hydrolysis of acetyl group from xylan, while FAEs release ferulic and other hydroxycinnamic acids from xylan and pectin. Previously, we reported a phylogenetic analysis for the fungal members of CE1, establishing five subfamilies (CE1_SF1-SF5). Currently, the characterized AXEs are in the subfamily CE1_SF1, whereas CE1_SF2 contains mainly characterized FAEs. These two subfamilies are more related to each other than to the other subfamilies and are predicted to have evolved from a common ancestor, but target substrates with a different molecular structure. In this study, four ascomycete enzymes from CE1_SF1 and SF2 were heterologously produced in Pichia pastoris and characterized with respect to their biochemical properties and substrate preference toward different model and plant biomass substrates. The selected enzymes from CE1_SF1 only exhibited AXE activity, whereas the one from CE1_SF2 possessed dual FAE/AXE activity. This dual activity enzyme also showed broad substrate specificity toward model substrates for FAE activity and efficiently released both acetic acid and ferulic acid (∼50%) from wheat arabinoxylan and wheat bran which was pre-treated with a commercial xylanase. These fungal AXEs and FAEs also showed promising biochemical properties, e.g., high stability over a wide pH range and retaining more than 80% of their residual activity at pH 6.0-9.0. These newly characterized fungal AXEs and FAEs from CE1 have high potential for biotechnological applications. In particular as an additional ingredient for enzyme cocktails to remove the ester-linked decorations which enables access for the backbone degrading enzymes. Among these novel enzymes, the dual FAE/AXE activity enzyme also supports the evolutionary relationship of CE1_SF1 and SF2.

Using high-resolution, aberration-corrected, scanning transmission electron microscopy and electron-energy-loss spectroscopy we show that in films of single-phase anatase Co: TiO 2 , the Co distribution and magnetic properties are strongly dependent both on the overall crystalline quality and postgrowth vacuum annealing process. The Co: TiO 2 films are coherent, epitaxial anatase with no secondary phases or metallic Co. Films of lower crystalline quality reveal a relatively homogeneous Co concentration, while films of higher crystalline quality show a tendency for Co enrichment near the surface region, around grain boundaries, and the substrate interface. Both uniform and nonuniform samples show a notable enhancement in the saturation magnetization with annealing, while the coercive field is considerably higher in the samples with uniform Co distribution. These experiments confirm that films of single-phase anatase Co: TiO 2 with both uniform and nonuniform Co distributions exhibit room-temperature ferromagnetism in the insulating ground state, while the compositional uniformity and film microstructure play a role in the bulk magnetic properties of the material and the mechanisms for ferromagnetic ordering.

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