Superparamagnetism in volcanic glasses of the KBS Tuff: Transmission electron microscopy and magnetic behavior

Charles M Schlinger, Rebecca M. Smith

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Volcanic glass separates (colorless to dark brown) from the KBS tuff of northern Kenya have been studied with a combination of transmission electron microscopy and low‐temperature ac susceptibility and dc magnetization experiments. The darker of these glasses exhibit classic superparamagnetic behavior, the origin of which lies in a spatially‐uniform precipitate of magnetite, which is present as ∼1% by weight in glass shards with the highest susceptibility. In any given glass separate (obtained by magnetic separation) this precipitate has a surprisingly narrow size distribution. A theory for the origin of the precipitate is nucleatation and growth in quenched glasses at temperatures of ∼1000‐1300°K; an experiment demonstrates the feasibility of this idea. These glasses provide us with a sample for experimental investigations of physical properties of naturally‐occurring dispersed magnetic phases at the lower limit of physical dimension that can be attained in the crystalline state.

Original languageEnglish (US)
Pages (from-to)729-732
Number of pages4
JournalGeophysical Research Letters
Volume13
Issue number8
DOIs
StatePublished - 1986
Externally publishedYes

Fingerprint

volcanic glass
tuff
transmission electron microscopy
volcanology
glass
precipitates
Kenya
magnetic permeability
magnetization
magnetite
physical property
experiment
physical properties
temperature

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

Cite this

Superparamagnetism in volcanic glasses of the KBS Tuff : Transmission electron microscopy and magnetic behavior. / Schlinger, Charles M; Smith, Rebecca M.

In: Geophysical Research Letters, Vol. 13, No. 8, 1986, p. 729-732.

Research output: Contribution to journalArticle

@article{d933b273cfb24acc945bc028b148dc06,
title = "Superparamagnetism in volcanic glasses of the KBS Tuff: Transmission electron microscopy and magnetic behavior",
abstract = "Volcanic glass separates (colorless to dark brown) from the KBS tuff of northern Kenya have been studied with a combination of transmission electron microscopy and low‐temperature ac susceptibility and dc magnetization experiments. The darker of these glasses exhibit classic superparamagnetic behavior, the origin of which lies in a spatially‐uniform precipitate of magnetite, which is present as ∼1{\%} by weight in glass shards with the highest susceptibility. In any given glass separate (obtained by magnetic separation) this precipitate has a surprisingly narrow size distribution. A theory for the origin of the precipitate is nucleatation and growth in quenched glasses at temperatures of ∼1000‐1300°K; an experiment demonstrates the feasibility of this idea. These glasses provide us with a sample for experimental investigations of physical properties of naturally‐occurring dispersed magnetic phases at the lower limit of physical dimension that can be attained in the crystalline state.",
author = "Schlinger, {Charles M} and Smith, {Rebecca M.}",
year = "1986",
doi = "10.1029/GL013i008p00729",
language = "English (US)",
volume = "13",
pages = "729--732",
journal = "Geophysical Research Letters",
issn = "0094-8276",
publisher = "American Geophysical Union",
number = "8",

}

TY - JOUR

T1 - Superparamagnetism in volcanic glasses of the KBS Tuff

T2 - Transmission electron microscopy and magnetic behavior

AU - Schlinger, Charles M

AU - Smith, Rebecca M.

PY - 1986

Y1 - 1986

N2 - Volcanic glass separates (colorless to dark brown) from the KBS tuff of northern Kenya have been studied with a combination of transmission electron microscopy and low‐temperature ac susceptibility and dc magnetization experiments. The darker of these glasses exhibit classic superparamagnetic behavior, the origin of which lies in a spatially‐uniform precipitate of magnetite, which is present as ∼1% by weight in glass shards with the highest susceptibility. In any given glass separate (obtained by magnetic separation) this precipitate has a surprisingly narrow size distribution. A theory for the origin of the precipitate is nucleatation and growth in quenched glasses at temperatures of ∼1000‐1300°K; an experiment demonstrates the feasibility of this idea. These glasses provide us with a sample for experimental investigations of physical properties of naturally‐occurring dispersed magnetic phases at the lower limit of physical dimension that can be attained in the crystalline state.

AB - Volcanic glass separates (colorless to dark brown) from the KBS tuff of northern Kenya have been studied with a combination of transmission electron microscopy and low‐temperature ac susceptibility and dc magnetization experiments. The darker of these glasses exhibit classic superparamagnetic behavior, the origin of which lies in a spatially‐uniform precipitate of magnetite, which is present as ∼1% by weight in glass shards with the highest susceptibility. In any given glass separate (obtained by magnetic separation) this precipitate has a surprisingly narrow size distribution. A theory for the origin of the precipitate is nucleatation and growth in quenched glasses at temperatures of ∼1000‐1300°K; an experiment demonstrates the feasibility of this idea. These glasses provide us with a sample for experimental investigations of physical properties of naturally‐occurring dispersed magnetic phases at the lower limit of physical dimension that can be attained in the crystalline state.

UR - http://www.scopus.com/inward/record.url?scp=84989554832&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84989554832&partnerID=8YFLogxK

U2 - 10.1029/GL013i008p00729

DO - 10.1029/GL013i008p00729

M3 - Article

AN - SCOPUS:84989554832

VL - 13

SP - 729

EP - 732

JO - Geophysical Research Letters

JF - Geophysical Research Letters

SN - 0094-8276

IS - 8

ER -