Magnetic and thermal properties of high  Tc  superconductors

Lee, Wonchoon

doi:10.2172/6534014

Cited by 1 publication

(1 citation statement)

References 80 publications

(180 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A signifi cant amount of effort has gone into laser probe analysis of millimeter-scale single crystals of mica and other phases (Lee et al 1990;Scaillet et al 1990;Onstott et al 1991;Hodges et al 1994;Arnaud and Kelley 1995;Reddy et al 1996;Pickles et al 1997). Results from these studies have demonstrated that laser ablation is capable of revealing signifi cant age variation in mm-scale crystals that could, under favorable circumstances, lead to thermal history constraints (Hodges et al 1994;Hames and Andresen 1996;Hames and Cheney 1997;Kelley and Wartho 2000;Wartho and Kelley 2003).…”

Section: Infering Closure Profiles From 40 Ar/ 39 Ar Datamentioning

confidence: 99%

Continuous Thermal Histories from Inversion of Closure Profiles

Harrison

Grove

Lovera

et al. 2005

Reviews in Mineralogy and Geochemistry

View full text Add to dashboard Cite

However, use of Equation (1) carries several stringent requirements. These include: knowledge of the activation energy, frequency factor, and compositional dependence of daughter product diffusion in the mineral of interest, a priori knowledge of the effective diffusion dimension, and assurance that volume diffusion was the rate limiting natural transport mechanism. Although adequate diffusion data are available for most commonly used minerals, it is only in rare cases that all these requirements are met. This represents a signifi cant limitation of thermochronometry. An example: the bulk closure temperature of biotite Consider the example of Ar closure in "biotite," which is typically taken to be 300 ± 50 °C (Purdy and Jäger 1976; Mattinson 1978; Harrison et al. 1979; Hodges 1991). This represents a nearly ideal case as the biotite-phlogopite solid solution is experimentally well-characterized in terms of Ar diffusion (Giletti 1974; Giletti and Tullis 1977; Harrison et al. 1985; Grove and Harrison 1996). Nevertheless, rigorous determination of a closure temperature requires that we know: 1) the effective diffusion length scale, 2) important compositional parameters such as Fe/Mg, Al(VI) occupancy, and halogen content, and 3) the approximate cooling rate and pressure during Ar closure (see Harrison and Zeitler 2005). For example, a biotite with an Fe/Mg of 0.6, an Al(VI) occupancy of 1.0, a total halogen content of 0.2%, and r = 150 µm, is characterized by a T c of 350 °C (assuming P = 200 MPa and dT/dt = 100 °C/Ma). However, increasing the total halogen content to 0.8% and decreasing Fe/Mg to 0.4 increases T c to about 450 °C (Grove 1993). Together with published estimates of r that vary by a factor of 6, extreme variations in compositional parameters yield a range in "biotite" T c of over 300 °C.

show abstract