磁性空位对HoFe$_{1-x}$Al$_x$O$_3$单晶自发自旋重取向转变的影响
Effect of Magnetic Vacancies on the Spontaneous Spin-Reorientation Transition in HoFe$_{1-x}$Al$_x$O$_3$ Single Crystals
AI总结：
本研究首次制备了铝掺杂浓度最高达x=0.2的HoFe₁₋ₓAlₓO₃单晶，发现磁性空位通过改变Ho³⁺离子相关各向异性的平衡，拓宽了磁相图中Γ₁₂相的稳定范围，揭示了空位对其自发自旋重取向转变的调控机制。
AI中文摘要：
本工作中，我们首次生长了铝浓度最高达$x=0.2$的HoFe$_{1-x}$Al$_x$O$_3$取代系列单晶，并研究了其自发自旋重取向转变（SRT）的演化规律。在稀土正铁氧体中，HoFeO$_3$呈现出独特的磁相序列（$Γ_4$-$Γ_{24}$-$Γ_{12}$-$Γ_2$）。这一复杂序列源于与Ho$^{3+}$离子相关的$K_{ac}$和$K_{ab}$各向异性，以及倾斜的Fe$^{3+}$亚晶格的弱铁磁矩产生的有效磁场之间的竞争。引入磁性空位会扰动$ab$平面内Fe$^{3+}$子系统的反铁磁补偿，并产生作用于Ho$^{3+}$离子的额外有效磁场。该磁场改变了SRT温度范围内$K_{ac}$与$K_{ab}$各向异性之间的平衡，从而拓宽了磁相图中$Γ_{12}$相的稳定范围。
英文摘要：
In this work, we report the first growth of single crystals of the substitution series HoFe$_{1-x}$Al$_x$O$_3$ with aluminium concentrations up to $x=0.2$ and investigate the evolution of their spontaneous spin-reorientation transition (SRT). Among rare-earth orthoferrites, HoFeO$_3$ exhibits a distinctive sequence of magnetic phases ($Γ_4$-$Γ_{24}$-$Γ_{12}$-$Γ_2$). This complex sequence arises from the competition between the $K_{ac}$ and $K_{ab}$ anisotropies associated with the Ho$^{3+}$ ions and the effective magnetic field produced by the weak ferromagnetic moment of the canted Fe$^{3+}$ sublattice. Introducing magnetic vacancies perturbs the antiferromagnetic compensation of the Fe$^{3+}$ subsystem in the $ab$ plane and generates an additional effective magnetic field acting on the Ho$^{3+}$ ions. This field alters the balance between the $K_{ac}$ and $K_{ab}$ anisotropies within the SRT temperature range and thereby broadens the stability range of the $Γ_{12}$ phase in the magnetic phase diagram.
