Julia Herrero-Albillos

Long-lived magnetism from solidification-driven convection on the pallasite parent body

Palaeomagnetic measurements of meteorites suggest that, shortly after the birth of the Solar System, the molten metallic cores of many small planetary bodies convected vigorously and were capable of generating magnetic fields. Convection on these bodies is currently thought to have been thermally driven, implying that magnetic activity would have been short-lived. Here we report a time-series palaeomagnetic record derived from nanomagnetic imaging of the Imilac and Esquel pallasite meteorites, a group of meteorites consisting of centimetre-sized metallic and silicate phases. We find a history of long-lived magnetic activity on the pallasite parent body, capturing the decay and eventual shutdown of the magnetic field as core solidification completed. We demonstrate that magnetic activity driven by progressive solidification of an inner core is consistent with our measured magnetic field characteristics and cooling rates. Solidification-driven convection was probably common among small body cores, and, in contrast to thermally driven convection, will have led to a relatively late (hundreds of millions of years after accretion), long-lasting, intense and widespread epoch of magnetic activity among these bodies in the early Solar System.

Magnetic ground state of CeNi1-xCux : A calorimetric investigation

We present a detailed specific heat study of the CeNi

Formation of Co Moment in the Paramagnetic Phase of RCo 2

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Parimagnetism: Strongly correlated paramagnetism in RCo2

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Nature and entropy content of the ordering transitions in RCo2

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Observation of a different magnetic disorder in Er Co 2

series in a large temperature range of 0.2 K to 300 K. The analysis of these data, considering also previous neutron scattering, magnetic characterization and

Photoemission electron microscopy of three-dimensional magnetization configurations in core-shell nanostructures

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Magnetic antidot to dot crossover in Co and Py nanopatterned thin films

SR results, allows us to present a convenient description of the system as inhomogeneous on the nanometric scale. Two regimes are detected in the compositional range depending on the dominant RKKY or Kondo interactions. We propose that the long-range magnetic order at low temperatures is achieved by a percolative process of magnetic clusters that become static below the freezing temperature

Nanopaleomagnetism of meteoritic Fe-Ni studied using X-ray photoemission electron microscopy

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Pallasite paleomagnetism: Quiescence of a core dynamo

. In this scenario the existence of a Quantum Critical Point at the magnetic-nonmagnetic crossover must be discarded.