Radial Variation of Magnetic Properties in Submarine Pillow Basalt

1975 ◽  
Vol 12 (12) ◽  
pp. 1959-1969 ◽  
Author(s):  
Patrick J. C. Ryall ◽  
J. M. Ade-Hall
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Low Temperature ◽  
Sea Water ◽  
Radial Variation ◽  
Cooling History ◽  
Pillow Basalt ◽  
Ridge Crest ◽  
Pillow Lavas ◽  
Mid Atlantic Ridge

A detailed study has been made of the magnetic properties of four pillow lavas of differing ages from the Mid-Atlantic Ridge crest at 45°N. The pillows show radial variations in grain size and concentration of titanomagnetite due to the initial cooling history, and radial variation in their degree of titanomagnetite oxidation due to low temperature alteration by sea-water. The degree of titanomagnetite alteration not only increases from the interior to the exterior of the pillows, it also increases from the youngest to the oldest. Radial variation in NRM intensity results in average values for the pillows of as little as half the values for the freshest parts. The direction of the original NRM has been maintained throughout the alteration.

Dynamics and magnetic properties of NO molecules encapsulated in open-cage fullerene derivatives evidenced by low temperature heat capacity

2021 ◽  
Author(s):  
Yoji Horii ◽  
Hal Suzuki ◽  
Yuji Miyazaki ◽  
Motohiro Nakano ◽  
Shota Hasegawa ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Magnetic Properties ◽  
Low Temperature ◽  
Magnetic Anisotropy ◽  
Fullerene Derivatives ◽  
Molecular Cages ◽  
Temperature Heat ◽  
Low Temperature Heat Capacity

Heat capacity analyses revealed dynamics and magnetic anisotropy of NO molecules confined in molecular cages.

scholarly journals X-ray diffraction analysis of kaolin M1 and M2 via the Williamson–Hall and Warren–Averbach methods

2021 ◽  
pp. 174751982098472
Author(s):  
Lalmi Khier ◽  
Lakel Abdelghani ◽  
Belahssen Okba ◽  
Djamel Maouche ◽  
Lakel Said
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Low Temperature ◽  
Diffraction Analysis ◽  
Mechanical Resistance ◽  
X Ray Diffraction ◽  
Integral Breadth ◽  
X Ray ◽  
Mullite Phase

Kaolin M1 and M2 studied by X-ray diffraction focus on the mullite phase, which is the main phase present in both products. The Williamson–Hall and Warren–Averbach methods for determining the crystallite size and microstrains of integral breadth β are calculated by the FullProf program. The integral breadth ( β) is a mixture resulting from the microstrains and size effect, so this should be taken into account during the calculation. The Williamson–Hall chart determines whether the sample is affected by grain size or microstrain. It appears very clearly that the principal phase of the various sintered kaolins, mullite, is free from internal microstrains. It is the case of the mixtures fritted at low temperature (1200 °C) during 1 h and also the case of the mixtures of the type chamotte cooks with 1350 °C during very long times (several weeks). This result is very significant as it gives an element of explanation to a very significant quality of mullite: its mechanical resistance during uses at high temperature remains.

Structural and low-temperature magnetic properties of as-quenched and annealed Ni–Si–B alloys produced by rapid solidification

2021 ◽  
Vol 132 ◽  
pp. 107140
Author(s):  
M. Ipatov ◽  
V. Zhukova ◽  
L. Dominguez ◽  
K.L. Alvarez ◽  
A. Chizhik ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Rapid Solidification

Holocene climate recorded by magnetic properties of lake sediments in the Northern Rocky Mountains, USA

The Holocene ◽  
2019 ◽  
Vol 30 (3) ◽  
pp. 479-484
Author(s):  
Daniel P Maxbauer ◽  
Mark D Shapley ◽  
Christoph E Geiss ◽  
Emi Ito
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Rocky Mountains ◽  
Future Research ◽  
Magnetic Minerals ◽  
Holocene Climate ◽  
Northern Rocky Mountains ◽  
The North ◽  
Lake Bottom ◽  
Northern Rockies

We present two hypotheses regarding the evolution of Holocene climate in the Northern Rocky Mountains that stem from a previously unpublished environmental magnetic record from Jones Lake, Montana. First, we link two distinct intervals of fining magnetic grain size (documented by an increasing ratio of anhysteretic to isothermal remanent magnetization) to the authigenic production of magnetic minerals in Jones Lake bottom waters. We propose that authigenesis in Jones Lake is limited by rates of groundwater recharge and ultimately regional hydroclimate. Second, at ~8.3 ka, magnetic grain size increases sharply, accompanied by a drop in concentration of magnetic minerals, suggesting a rapid termination of magnetic mineral authigenesis that is coeval with widespread effects of the 8.2 ka event in the North Atlantic. This association suggests a hydroclimatic response to the 8.2 ka event in the Northern Rockies that to our knowledge is not well documented. These preliminary hypotheses present compelling new ideas that we hope will both highlight the sensitivity of magnetic properties to record climate variability and attract more work by future research into aridity, hydrochemical response, and climate dynamics in the Northern Rockies.

scholarly journals Investigation of Polyol Process for the Synthesis of Highly Pure BiFeO3 Ovoid-Like Shape Nanostructured Powders

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 26 ◽  
Author(s):  
Manel Missaoui ◽  
Sandrine Coste ◽  
Maud Barré ◽  
Anthony Rousseau ◽  
Yaovi Gagou ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
High Purity ◽  
Average Crystallite Size ◽  
Polyol Process ◽  
Pure Bifeo3 ◽  
Optimum Parameters ◽  
Mössbauer Measurements ◽  
Synthesis Protocol ◽  
Nanostructured Powders

Exclusive and unprecedented interest was accorded in this paper to the synthesis of BiFeO3 nanopowders by the polyol process. The synthesis protocol was explored and adjusted to control the purity and the grain size of the final product. The optimum parameters were carefully established and an average crystallite size of about 40 nm was obtained. XRD and Mössbauer measurements proved the high purity of the synthesized nanostructurated powders and confirmed the persistence of the rhombohedral R3c symmetry. The first studies on the magnetic properties show a noticeable widening of the hysteresis loop despite the remaining cycloidal magnetic structure, promoting the enhancement of the ferromagnetic order and consequently the magnetoelectric coupling compared to micrometric size powders.

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