Ferri-para-magnetism of tungsten and its carbide cermets for elevated temperature sensor application

Autor: Swe-Kai Chen, Yeu-Tiing Tsai, Bo-Wen Jou
Rok vydání: 2018
Předmět:
Zdroj: Chinese Journal of Physics. 56:303-307
ISSN: 0577-9073
DOI: 10.1016/j.cjph.2017.12.011
Popis: In routinely analyzing experimental results of low-temperature, 5 K ≤ T ≤ 300 K, magnetic susceptibility χ(T) of fused tungsten and its fused carbide cermets, hereafter called “the materials”, by assuming the susceptibility satisfying the Neel ferrimagnetic formula, χ−1 = χ0−1 + χ1−1 + χ2−1, where χ0−1, χ1−1, and χ2−1 are respectively the inverses of the Pauli paramagnetic, χ0 > 0, a Curie diamagnetic, χ1 = C/T 300 K) temperatures, one finds two singular points in the susceptibility inverse curve χ−1. One is at Θp > 0, e.g., Θp = −1.73 K, and Θa = −C/χ0 = +8655 K for tungsten. In view of their susceptibility precisely satisfying the Neel ferrimagnetic formula in the temperature range of 5 K and 300 K, they are called “ferri-para-magnetism” and are good for elevated temperature sensor application if the temperature extension is satisfied. As temperature exceeding an asymptotic temperature, Θa, the paramagnetic state turns to a diamagnetic state, suggesting that there might be a superconducting transition at this temperature for some of the materials with Θas that are lower than their melting points, e.g., Θa(C7M1) = +2735 K and Θa(-VC) = +2242 K.
Databáze: OpenAIRE