npsm 새물리 New Physics : Sae Mulli

pISSN 0374-4914 eISSN 2289-0041


Research Paper

New Phys.: Sae Mulli 2020; 70: 909-913

Published online November 30, 2020

Copyright © New Physics: Sae Mulli.

Effects of Partial Substitution of Nitrate on the Superconducting Properties of TlSr$_{4}$Cu$_{2}$O$_{z}$(SO$_{4}$)

Ho Keun LEE*

Department of Physics, Kangwon National University, Chuncheon 24341, Korea


Received: August 29, 2020; Revised: September 24, 2020; Accepted: September 24, 2020


The effects of partial substitution of nitrate groups at the SO$_{4}$ sites on the superconducting properties of the TlSr$_{4}$Cu$_{2}$O$_{z}$(SO$_{4}$)$_{1-x}$(NO$_{3}$)$_{x}$ system have been investigated. X-ray diffraction data showed that the solubility limit of (NO$_{3}$) was about $x$ = 0.35. The change in the solubility limit of oxyanion for sulfate was discussed in connection with the characteristics of the oxyanion species. Within the solubility limit, the introduction of the nitrate groups did not change significantly the transition temperature of the pristine TlSr$_{4}$Cu$_{2}$O$_{z}$(SO$_{4}$) compound. However, we found that compared to the pristine compound, the introduction of the nitrate groups degraded the stability properties of the sample after annealing at 400$^{\circ}$C in Ar atmosphere.

Keywords: Oxyanion superconductors, Nitrate substitution, Stability, TlSr$_{4}$Cu$_{2}$O$_{z}$ (SO$_{4}$)$_{1-x}$(NO$_{3}$)$_{x}$

SO$_{4}$ 대신NO$_{3}$ 를 부분치환한 TlSr$_{4}$Cu$_{2}$O$_{z}$(SO$_{4}$)$_{1-x}$(NO$_{3}$)$_{x}$ 계의 초전도 특성에 대해 연구했다. X-선 회절 분석 결과는 (NO$_{3}$)의 고용한계는 약 0. 35 임을 보여주었으며, 황산화물 음이온자리에 다른 음이온이 치환될 때의 고용한계 차이를 음이온 종류의 특성과 연관해 논의했다. 비저항 측정결과 임계온도 특성은 고용한계내에서 임계온도의 변화가 매우 적음을 보여주었다. 그러나 Ar 분위기에서 400 $^{\circ}$C로 열처리한 후의 비저항 측정결과는 NO$_{3}$를 치환하지 않은 시편의 특성과 비교하였을 때 안정도 특성이 나빠짐을 보여주었다

Keywords: 산화 음이온 초전도체, NO$_{3}$치환, 안정도, TlSr$_{4}$Cu$_{2}$O$_{z}$(SO$_{4}$)$_{1-x}$(NO$_{3}$)$_{x}$


Fig. 1. Temperature dependences of the electrical resistivity for TlSr$_{4}$Cu$_{2}$O$_{z}$(SO$_{4}$)$_{1-x}$(NO$_{3}$)$_{x}$ samples.

Stats or Metrics

Share this article on :

Related articles in NPSM