Recent research activities on the linear magnetoelectric (ME) effect?induction of magnetization by an electric field or of polarization by a magnetic field?are reviewed. Beginning with a brief summary of the history of the ME effect since its prediction in 1894, the paper focuses on the present revival of the effect. Two major sources for 'large' ME effects are identified. (i) In composite materials the ME effect is generated as a product property of a magnetostrictive and a piezoelectric compound. A linear ME polarization is induced by a weak ac magnetic field oscillating in the presence of a strong dc bias field. The ME effect is large if the ME coefficient coupling the magnetic and electric fields is large. Experiments on sintered granular composites and on laminated layers of the constituents as well as theories on the interaction between the constituents are described. In the vicinity of electromechanical resonances a ME voltage coefficient of up to 90?V?cm?1?Oe?1 is achieved, which exceeds the ME response of single-phase compounds by 3?5 orders of magnitude. Microwave devices, sensors, transducers and heterogeneous read/write devices are among the suggested technical implementations of the composite ME effect. (ii) In multiferroics the internal magnetic and/or electric fields are enhanced by the presence of multiple long-range ordering. The ME effect is strong enough to trigger magnetic or electrical phase transitions. ME effects in multiferroics are thus 'large' if the corresponding contribution to the free energy is large. Clamped ME switching of electrical and magnetic domains, ferroelectric reorientation induced by applied magnetic fields and induction of ferromagnetic ordering in applied electric fields were observed. Mechanisms favouring multiferroicity are summarized, and multiferroics in reduced dimensions are discussed. In addition to composites and multiferroics, novel and exotic manifestations of ME behaviour are investigated. This includes (i) optical second harmonic generation as a tool to study magnetic, electrical and ME properties in one setup and with access to domain structures; (ii) ME effects in colossal magnetoresistive manganites, superconductors and phosphates of the LiMPO4 type; (iii) the concept of the toroidal moment as manifestation of a ME dipole moment; (iv) pronounced ME effects in photonic crystals with a possibility of electromagnetic unidirectionality. The review concludes with a summary and an outlook to the future development of magnetoelectrics research.

https://iopscience.iop.org/article/10.1088/0022-3727/38/8/R01/pdf

Revival of the Magnetoelectric Effect

Multiferroic materials, which show simultaneous ferroelectric and magnetic ordering, exhibit unusual physical properties — and in turn promise new device applications — as a result of the coupling between their dual order parameters. We review recent progress in the growth, characterization and understanding of thin-film multiferroics. The availability of high-quality thin-film multiferroics makes it easier to tailor their properties through epitaxial strain, atomic-level engineering of chemistry and interfacial coupling, and is a prerequisite for their incorporation into practical devices. We discuss novel device paradigms based on magnetoelectric coupling, and outline the key scientific challenges in the field.

Multiferroics: progress and prospects in thin films.

Over the past several years, cerium oxide and CeO2-containing materials have come under intense scrutiny as catalysts and as structural and electronic promoters of heterogeneous catalytic reactions. Recent developments regarding the characterization of ceria and CeO2-containing catalysts are critically reviewed with a special focus towards catalyst interaction with small molecules such as hydrogen, carbon monoxide, oxygen, and nitric oxide. Relevant catalytic and technological applications such as the use of ceria in automotive exhaust emission control and in the formulation of SO x reduction catalysts is described. A survey of the use of CeO2-containing materials as oxidation and reduction catalysts is also presented.

Catalytic Properties of Ceria and CeO2-Containing Materials

The development of novel materials is a fundamental focal point of chemical research; and this interest is mandated by advancements in all areas of industry and technology. A good example of the synergism between scientific discovery and technological development is the electronics industry, where discoveries of new semiconducting materials resulted in the evolution from vacuum tubes to diodes and transistors, and eventually to miniature chips. The progression of this technology led to the development * To whom correspondence should be addressed. B.L.C.: (504) 2801385 (phone); (504) 280-3185 (fax); bcushing@uno.edu (e-mail). C.J.O.: (504)280-6846(phone);(504)280-3185(fax);coconnor@uno.edu (e-mail). 3893 Chem. Rev. 2004, 104, 3893−3946

http://depa.fquim.unam.mx/amyd//archivero/FidelmarLechugaSanabria_4940.pdf

Recent advances in the liquid-phase syntheses of inorganic nanoparticles.

Cerium dioxide (CeO2, ceria) is becoming an ubiquitous constituent in catalytic systems for a variety of applications. 2016 sees the 40th anniversary since ceria was first employed by Ford Motor Company as an oxygen storage component in car converters, to become in the years since its inception an irreplaceable component in three-way catalysts (TWCs). Apart from this well-established use, ceria is looming as a catalyst component for a wide range of catalytic applications. For some of these, such as fuel cells, CeO2-based materials have almost reached the market stage, while for some other catalytic reactions, such as reforming processes, photocatalysis, water-gas shift reaction, thermochemical water splitting, and organic reactions, ceria is emerging as a unique material, holding great promise for future market breakthroughs. While much knowledge about the fundamental characteristics of CeO2-based materials has already been acquired, new characterization techniques and powerful theoretical methods are dee...

Fundamentals and Catalytic Applications of CeO2-Based Materials

Effects of the addition of precious metals (PM; Pt, Rh) on CeO{sub 2}/Al{sub 2}O{sub 3} and CeO{sub 2}/La{sub 2}O{sub 3}/Al{sub 2}O{sub 3} were confirmed to enhance the oxygen storage capacities (OSC). Increments in the OSC of the added CeO{sub 2}/La{sub 2}O{sub 3}/Al{sub 2}O{sub 3} catalysts were much greater than those in the OSC of the PM added CeO{sub 2}/Al{sub 2}O{sub 3}. The enhanced OSC is ascribed to the interaction between PM and a CeO{sub 2}-La{sub 2}O{sub 3} solid solution formed during the catalyst preparation. No enhancements in the OSC were observed on physical mixing of CeO{sub 2}/La{sub 2}O{sub 3}/Al{sub 2}O{sub 3} and Pt-Rh/Al{sub 2}O{sub 3}, although the composition ratio of PM:CeO{sub 2}:La{sub 2}O{sub 3} is the same as that in the PM added CeO{sub 2}/La{sub 2}O{sub 3}/Al{sub 2}O{sub 3}. This indicates that the intimate contacts between the precious metals and CeO{sub 2} particles dispersed on Al{sub 2}O{sub 3} are essential for the enhanced OSC of cerium oxides.

Enhanced oxygen storage capacity of cerium oxides in cerium dioxide/lanthanum sesquioxide/alumina containing precious metals

Nickel oxide electrochromic thin films were prepared by reactive DC magnetron sputtering. The as-deposited optical property and electrochromic behavior strongly depended on the target operation mode and the substrate temperature. The sample sputtered with low oxygen flow rate, high power and substrate temperature of 200-300° C showed a wide transmittance modulation range, and the deposition rate was as high as 30 nm/min. Its integrated luminous transmittance could be controlled from 6.6 to 82.3%. X-ray diffraction measurements of this sample in a colored state and bleached state suggested that the boundary and surface of NiO microcrystallites played an important role in the electrochromic reaction of sputtered nickel oxide films.

https://iopscience.iop.org/article/10.1143/JJAP.34.2440/pdf

Nickel Oxide Electrochromic Thin Films Prepared by Reactive DC Magnetron Sputtering

Dielectric and piezoelectric properties of highly (1 0 0)-oriented BaTiO3 thin film grown on a Pt/TiOx/SiO2/Si substrate using LaNiO3 as a buffer layer

Characterization of niobium oxide electrochromic thin films prepared by reactive d.c. magnetron sputtering

CaBi4Ti4O15 (CBTi144) thin films were prepared by spin coating a precursor solution of metal alkoxides. As-deposited thin films began crystallization below 550 °C and reached full crystallinity of a single phase of layered perovskite at 650 °C via rapid thermal annealing in oxygen. The 650 °C annealed CBTi144 thin film showed random orientation on Pt-passivated Si substrate and exhibited P-E hysteresis loops. The remanent polarization (Pr) and coercive electric field (Ec) were 9.4 μC/cm2 and 106 kV/cm, respectively, at 11 V. The dielectric constant and loss factor were 300 and 0.033, respectively, at 100 kHz.

Takeshi Miki

Papers

Enhanced oxygen storage capacity of cerium oxides in cerium dioxide/lanthanum sesquioxide/alumina containing precious metals

Nickel Oxide Electrochromic Thin Films Prepared by Reactive DC Magnetron Sputtering

Dielectric and piezoelectric properties of highly (1 0 0)-oriented BaTiO3 thin film grown on a Pt/TiOx/SiO2/Si substrate using LaNiO3 as a buffer layer

Characterization of niobium oxide electrochromic thin films prepared by reactive d.c. magnetron sputtering

Ferroelectric properties of alkoxy-derived CaBi4Ti4O15 thin films on Pt-passivated Si