Novel Ir1–xCoxO2 thin films: Growth and characterization

Ir1–xCoxO2 thin films have been prepared by reactive co–sputtering deposition at room temperature. Composition, structure, electronic properties and electric and magnetic behavior have been analyzed by different techniques including XRR, XRD, TEM microscopy, SQUID magnetometry, electrical resistivity and XAS spectroscopy. After annealing, an Ir1–xCoxO2 substitutional solid solution phase with rutile crystal structure was achieved for a wide Co-doping range 0 ≤ x ≤ 0.6. Starkly departing from the highly insulating behavior of CoO and Co3O4, the electrical resistivity at room temperature of our films is only slightly higher than that of IrO2. Likewise, our work shows that the magnetic response of the doped films is very similar to that of the paramagnetic parent IrO2. Neither ferromagnetism nor enhanced paramagnetism is observed. XAS spectra indicate a Co3+ oxidation state and, correspondingly, an oxidation state of ∼5+ for Ir ions in the polycrystalline Ir0.6Co0.4O2 film. By application of sum rules, a 13 % increase in the spin–orbit coupling is found despite the lattice shrinkage causes a detrimental bandwidth broadening

Microstructural and magnetic characterization of Fe- and Ir-based multilayers

Nominal [Fe(t)/Ir(t'')](n) (M/Mtype), [FeOx(t)/IrOx(t'')](n) (O/O), and [Fe(t)/IrOx(t'')](n) (M/O) multilayers have been prepared by magnetron sputtering at room temperature. Composition, structure, and magnetic behavior have been analyzed. In the M/M samples, the Fe and Ir phases are identified as bcc and fcc, respectively. The magnetism evolves from bulklike iron to granular behavior as the thickness of the Fe layers decreases. An induced magnetic moment, ferromagnetically coupled to Fe, is observed on Ir by x-ray magnetic circular dichroism (XMCD). Besides, the presence of negative remanent magnetization is observed in the M/M samples. As for the M/O samples, the stronger affinity of iron for oxygen displaces the oxygen atoms giving rise to actual heterostructures that strongly differ from the nominal ones. For similar thickness of the two layers the Fe layer become oxidized while a mixture of metal and oxide phases is found in the Ir layer. The increase of the Fe thickness leads to a metallic Ir layer and a highly coercive (similar to 4.4 kOe) core-shell metal-oxide structure in the Fe layers

Microstructural and magnetic characterization of Fe- and Ir-based multilayers

Nominal [Fe(t)/Ir(t′)]n (M/M type), [FeOx(t)/IrOx(t′)]n (O/O), and [Fe(t)/IrOx(t′)]n (M/O) multilayers have been prepared by magnetron sputtering at room temperature. Composition, structure, and magnetic behavior have been analyzed. In the M/M samples, the Fe and Ir phases are identified as bcc and fcc, respectively. The magnetism evolves from bulklike iron to granular behavior as the thickness of the Fe layers decreases. An induced magnetic moment, ferromagnetically coupled to Fe, is observed on Ir by x-ray magnetic circular dichroism (XMCD). Besides, the presence of negative remanent magnetization is observed in the M/M samples. As for the M/O samples, the stronger affinity of iron for oxygen displaces the oxygen atoms giving rise to actual heterostructures that strongly differ from the nominal ones. For similar thickness of the two layers the Fe layer become oxidized while a mixture of metal and oxide phases is found in the Ir layer. The increase of the Fe thickness leads to a metallic Ir layer and a highly coercive (∼4.4 kOe) core-shell metal-oxide structure in the Fe layers.Spanish Ministry of Economy and Competitiveness (MINECO), MAT2014-54425-R, MAT2017-83468-RAragón DGA NETOSHIM

Características físico-químicas e perfil lipídico do leite de cabras mestiças Moxotó alimentadas com dietas suplementadas com óleo de semente de algodão ou de girassol Physico-chemical characteristics and fatty acid profile of milk of crossbred Moxotó goats supplemented with cottonseed or sunflower oil

O efeito da suplementação com óleos de algodão e de girassol sobre a composição do leite foi testado em cabras mestiças Moxotó alimentadas com cinco dietas: controle, sem adição de óleo; adição de óleo de algodão a 3%; óleo de algodão a 5%; óleo de girassol a 3%; e óleo de girassol a 5% (%MS). Foram utilizadas dez cabras em lactação, confinadas, distribuídas em dois quadrados latinos (5 &times; 5), com 12 dias de adaptação e três dias de coleta em cada período. A suplementação com óleo de algodão a 5% MS elevou o teor de gordura (4,99%) e de extrato seco total (13,48%) do leite, mas não alterou a concentração dos demais componentes. A adição de 5% de óleo de girassol, no entanto, promoveu aumento na concentração do ácido linolênico (C18:3). A adição de óleo vegetal em dietas para cabras nativas promoveu aumento do percentual de gordura no leite e aumento nos teores de ácidos graxos insaturados resultando em um produto de melhor qualidade para a saúde humana.<br>The effects of cottonseed and sunflower oil supplementation on milk composition were tested using crossbred Moxotó goats. Experimental diets were as follows: control, without addition of oil; addition of 3% cottonseed oil; 5% cottonseed oil; 3% sunflower oil and 5% sunflower oil (%DM). Ten confined lactating goats were allotted to a double Latin square experimental design (5 &times; 5). Each period was comprised by 12 days of adaptation to the diet and three days of sampling in each period. Cottonseed oil supplementation at 5 %DM increased the fat content (4.99%) and the total solid (13.48%) of milk. However, the addition of sunflower oil at 5% promoted an increase in the linolenic acid (C18:3) concentrations. Therefore, the vegetal oil addition in diets for native goats promoted an increase in the percentage of milk fat and in unsaturated fatty acid contents in milk, resulting in a product of better quality for the human health