Multifunctional Gd³⁺, Dy³⁺ and Yb³⁺ cosubstitutions in β-Ca₃(PO₄)₂ were achieved through a facile synthetic technique. Gd³⁺ and Dy³⁺ prefer to occupy the 7-fold coordinated Ca²⁺(1), 6- or 8-fold coordinated Ca²⁺(2), and 8-fold coordinated Ca²⁺(3) sites of the β-Ca₃(PO₄)₂ structure. The shortest Ca(5)—O bond length of te Ca²⁺(5) site with 6-fold co-ordination favors Yb³⁺ accommodation. The substitution limit of each dopant to attain β-Ca₃(PO₄)₂ solid solution is determined as ∼1.25 mol %. The combined substitutions displayed upconversion emission in blue, yellow and red regions on excitation at 980 nm via the energy transfer mechanism from Yb³⁺ to Dy³⁺. Yb³⁺ and Dy³⁺ combination induces a high X-ray absorption ability for computed tomography (CT). The materials also displayed paramagnetic behavior and exhibited high longitudinal (r₁ = 48.71 mM^–1 s^–1) and transverse relaxivity (r₂ = 61.79 mM^–1 s^–1) indicating their potential as T₁ and T₂ contrast agents in magnetic resonance imaging (MRI). The negligible toxicity of Gd³⁺/Dy³⁺/Yb³⁺ cosubstitutions in β-Ca₃(PO₄)₂ is also demonstrated. The overall results justify the potential of the developed material as possible contrast agent for T₁ and T₂ MRI/CT/upconversion luminescence.

中文翻译：

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镧系元素的Cosubstitution（GD ³⁺ / DY ³⁺ /镱³⁺）在β-的Ca ₃（PO ₄）₂进行上转换发光，CT / MRI多模成像

多官能的Gd ³⁺，镝³⁺和Yb ³⁺在β-钙cosubstitutions ₃（PO ₄）₂是通过一个浅显的合成技术来实现的。Gd ³⁺和Dy ³⁺倾向于占据7位配位的Ca ²⁺（1），6位或8位配位的Ca ²⁺（2）和8位配位的Ca ²⁺（3）位置。 β-的Ca ₃（PO ₄）₂的结构。te Ca ²⁺（5）位置具有6倍配位的最短Ca（5）-O键长度有利于Yb ³⁺住所。每一种掺杂剂的取代极限达到β-的Ca ₃（PO ₄）₂固溶体被确定为~1.25摩尔％。组合的取代基通过从Yb ³⁺到Dy ³⁺的能量转移机制在980 nm激发时在蓝色，黄色和红色区域显示上转换发射。Yb ³⁺和Dy ^3+的组合对计算机断层扫描（CT）具有较高的X射线吸收能力。这些材料还表现出顺磁特性，并具有较高的纵向（r ₁ = 48.71 mM ^–1 s ^–1）和横向弛豫性（r ₂ = 61.79 mM）^–1 s ^–1）表示它们在磁共振成像（MRI）中作为T ₁和T ₂造影剂的潜力。Gd组成的可忽略的毒性³⁺ / DY ³⁺ /镱³⁺ cosubstitutions在β-的Ca ₃（PO ₄）₂也被证实。总体结果证明了所开发材料作为T ₁和T ₂ MRI / CT /上转换发光可能的造影剂的潜力。