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The possibility to tune the magnetic properties of materials with voltage (converse magnetoelectricity) or to generate electric voltage with magnetic fields (direct magnetoelectricity) has opened new avenues in a large variety of technological fields, ranging from information technologies to healthcare devices and including a great number of multifunctional integrated systems such as mechanical antennas, magnetometers, radiofrequency (RF) tunable inductors, etc., which have been realized due to the strong strainmediated magnetoelectric (ME) coupling found in ME composites. The development of singlephase multiferroic materials (which exhibit simultaneous ferroelectric and ferromagnetic or antiferromagnetic orders), multiferroic heterostructures, as well as progress in other ME mechanisms, such as electrostatic surface charging or magneto-ionics (voltage-driven ion migration) have a large potential to boost energy efficiency in spintronics and magnetic actuators. This paper focuses on existing ME materials and devices and reviews the state of the art in their

Magnetoelectric thin film composites have demonstrated their potential to detect sub-pT magnetic fields if mechanical resonances (typically few hundred Hz to a few kHz) are utilized. At low frequencies (1–100 Hz), magnetic field-induced frequency conversion has enabled wideband measurements with resonance-enhanced sensitivities by using the nonlinear characteristics of the magnetostriction curve. Nevertheless, the modulation with a magnetic field with a frequency close to the mechanical resonance results in a number of drawbacks, which are, e.g., size and energy consumption of the sensor as well as potential crosstalk in sensor arrays. In this work, we demonstrate the feasibility of an electric frequency conversion of a magnetoelectric sensor which would overcome the drawbacks of magnetic frequency conversion. This magnetoelectric sensor consists of three functional layers: an exchange biased magnetostrictive multilayer showing a high piezomagnetic coefficient without applying a magnetic bias field, a non-linear piezoelectric actuation layer and a linear piezoelectric sensing layer. In this approach, the low frequency magnetic signal is shifted into the mechanical resonance of the sensor, while the electric modulation frequency is chosen to be either the difference or the sum of the resonance and the signal frequency. Using this electric frequency conversion, a limit of detection in the low nT/Hz1/2 range was shown for signals of low frequency.

The strong strain-mediated magnetoelectric (ME) coupling found in thin-film ME heterostructures has attracted an ever-increasing interest and enables realization of a great number of integrated multiferroic devices, such as magnetometers, mechanical antennas, RF tunable inductors and filters. This paper first reviews the thin-film characterization techniques for both piezoelectric and magnetostrictive thin films, which are crucial in determining the strength of the ME coupling. After that, the most recent progress on various integrated multiferroic devices based on thin-film ME heterostructures are presented. In particular, rapid development of thin-film ME magnetometers has been seen over the past few years. These ultra-sensitive magnetometers exhibit extremely low limit of detection (sub-pT/Hz1/2) for low-frequency AC magnetic fields, making them potential candidates for applications of medical diagnostics. Other devices reviewed in this paper include acoustically actuated nanomechanical ME antennas with miniaturized size by 1–2 orders compared to the conventional antenna; integrated RF tunable inductors with a wide operation frequency range; integrated RF tunable bandpass filter with dual H- and E-field tunability. All these integrated multiferroic devices are compact, lightweight, power-efficient, and potentially integrable with current complementary metal oxide semiconductor (CMOS) technology, showing great promise for applications in future biomedical, wireless communication, and reconfigurable electronic systems.

One hundred and seventy‐nine yellow pigmented Gram negative rods, including 170 new isolates obtained from a variety of habitats, were investigated and the results analysed by computer. Nine phena, embracing 146 strains, were distinguished. Five of these comprised 88 of the 109 non‐motile, aflagellate strains (i.e. ‘atypical cytophagas’) and they should be assigned to a re‐defined genus Flavobacterium. A separate phenon containing 41 of the gliding isolates was delineated which should be ascribed provisionally to the genus Flexibacter. Only low G + C contents have been recorded for representative strains from these six phena but one strain (which would have been ascribed to Flavobacterium) had a high G + C content; such organisms (both peritrichous and non‐motile) should comprise a separate genus Empedobacter (Brisou). The remaining three phena respectively comprised strains of Erwinia herbicola, pseudomonads and unclassified aflagellate isolates; their taxonomic position is discussed.

SUMMARYAn Adansonian analysis of the features of 62 yellow pigmented marine bacteria, all but one of which were identified as Flavobacterium species by the workers who isolated them, revealed that 34 fell into one of two large pleista or groups; the rest fell into smaller pleista, or were the sole representative of their pleiston present, The possibility that these pleista approximate to various established genera is discussed.

Magnetoelectric (ME) thin film composites consisting of sputtered piezoelectric (PE) and magnetostrictive (MS) layers enable for measurements of magnetic fields passively, i.e. an AC magnetic field directly generates an ME voltage by mechanical coupling of the MS deformation to the PE phase. In order to achieve high field sensitivities a magnetic bias field is necessary to operate at the maximum piezomagnetic coefficient of the MS phase, harnessing mechanical resonances further enhances this direct ME effect size. Despite being able to detect very small AC field amplitudes, exploiting mechanical resonances directly, implies a limitation to available signal bandwidth along with the inherent inability to detect DC or very low frequency magnetic fields. The presented work demonstrates converse ME modulation of thin film Si cantilever composites of mesoscopic dimensions (25 mm × 2.45 mm × 0.35 mm), employing piezoelectric AlN and magnetostrictive FeCoSiB films of 2 µm thickness each. A high frequency mechanical resonance at about 515 kHz leads to strong induced voltages in a surrounding pickup coil with matched self-resonance, leading to field sensitivities up to 64 kV/T. A DC limit of detection of 210 pT/Hz1/2 as well as about 70 pT/Hz1/2 at 10 Hz, without the need for a magnetic bias field, pave the way towards biomagnetic applications.

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