【摘要】 本文首先仔细地介绍了浮区法生长Y掺杂的(Tb1-xYx)2Ti2O7单晶(x=0,0.1,0.5)的条件,并基于高品质的单晶样品,详细地研究了其磁性质、比热及热输运行为.(Tb1-xYx)2Ti2O7单晶在～80K时开始出现短程磁关联相互作用,非磁性离子Y3+的掺杂稀释了Tb3+的浓度,削弱了体系中的磁关联相互作用并引起了局部晶格的畸变,导致晶体场能级劈裂的加剧,而磁场则会增强体系中的关联相互作用,同时塞曼效应加剧了双重态能级的劈裂.热导率测量中发现Tb3+间的磁关联相互作用引起的自旋涨落抑制了声子的导热,而Y的掺杂并没有根本性地破坏这种关联相互作用.更多还原

【Abstract】 In this paper,the crystal growth conditions of nonmagnetic Y-doped(Tb1-xYx)Ti2O7(x = 0,0.1,0.5) single crystals using floating zone technique are reported in detail.The magnetic properties,specific heat and thermal conductivities are carefully studied on high quality(Tb1-xYx)Ti2O7 single crystals.It is found that the short range correlations appear at 80 K and the nonmagnetic ion Y3+ doping dilutes the concentration of Tb3+,leading to the weakness of magnetic correlations and emergence of lattice distortions,which will enlarge the crystal field splitting.In addition,the magnetic correlations are strengthened in magnetic field and the energy splitting of the doublets is increased by the Zeeman effect.The measurements of thermal conductivities indicate that phonons are strongly scattered by spin fluctuations,and Y-doping does not fundamentally destroy the magnetic correlations.更多还原