摘要
系统研究了Gd5Ge4合金的晶体结构和低温磁化行为。结果表明,Gd5Ge4具有相分离特征,低温下出现反铁磁(AFM)和铁磁(FM)共存现象。由于相分离的存在导致127K时发生奈尔反铁磁转变。在外磁场诱导下,在4.2K以下发生AFM-FM磁转变,并导致台阶式磁化现象发生,但仅发生在第一次外加磁场增加过程中,表现出磁不可逆性。随磁场升高,在10K以下体系存在类台阶式响应和不可逆的磁滞行为,并在5572kA/m下均达到饱和磁化。在温度50~60K温区,磁循环所出现的台阶式磁化转变则是完全可逆的,更高温区域则表现为部分铁磁直至室温下的顺磁特性。
Crystal structure and magnetization behavior at low temperature were studied systematically /or Gd5Ge4 alloy. The results show that Gd5Ge4 is a phase-separated alloy and has antiferromagnetic (AFM) state and ferromagnetic (FM) state coexisting at low temperature. Abnormal N6el transition occurs at 127K due to phase separation. Below 4.2K,AFM-FM transition induced by magnetic field can occur in Gd5Ge4, the transition is the main reason for magnetization step transition, and the magnetic transition only occurs when the magnetic field firstly increases, so it is irreversible. With magnetic field increasing,below 10K, there exist magnetization step behavior and hysteresis behavior, and the magnetization value reach saturation at 5572kA/m. At temperature 50-60K, the second magnetization almost goes along the first magnetization path, so the magnetization is entirely reversible. The Gd5Ge4 alloy is partly ferromagnetism below 120K and is completely para-mag- netism at room temperature.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2009年第11期1798-1801,共4页
Journal of Functional Materials
基金
国家自然科学基金资助项目(10875107
10774097)
上海市科学技术委员会重点基础研究计划资助项目(07JC14022)
河南省自然科学基金资助项目(082300440080)
河南省教育厅自然科学基础研究计划资助项目(2008A140014)
关键词
Gd5Ge4合金
低温磁性
相分离
台阶式磁化跳跃
Gd5Ge4 alloy
low-temperature magnetic properties
phase separation
step magnetization