Yakubovich Olga V, Shvanskaya Larisa V, Dimitrova Olga V, Volkova Olga S, Vasiliev Alexander N
M. V. Lomonosov Moscow State University, Moscow 119991, Russia.
Dalton Trans. 2017 Jul 4;46(26):8680-8686. doi: 10.1039/c7dt01707c.
The manganese end member of triplite-triploidite series of compounds, Mn(PO)OH, is synthesized by a hydrothermal method. Its crystal structure is refined in the space group P2/c with a = 12.411(1) Å, b = 13.323(1) Å, c = 10.014(1) Å, β = 108.16(1), V = 1573.3 Å, Z = 8, and R = 0.0375. Evidenced in measurements of magnetization M and specific heat C, Mn(PO)OH reaches a long range antiferromagnetic order at T = 4.6 K. As opposed to both triplite Mn(PO)F and triploidite-type Co(PO)F, the title compound is magnetically frustrated being characterized by the ratio of Curie-Weiss temperature Θ to Néel temperature T of about 20. The large value of frustration strength |Θ|/T stems from the twisted saw tooth chain geometry of corner sharing triangles of Mn polyhedra, which may be isolated within tubular fragments of a triploidite crystal structure.
通过水热法合成了磷锰矿 - 三斜磷锰矿系列化合物的锰端元成员Mn(PO₄)OH。其晶体结构在空间群P2/c中精修，a = 12.411(1) Å，b = 13.323(1) Å，c = 10.014(1) Å，β = 108.16(1)，V = 1573.3 Å，Z = 8，R = 0.0375。在磁化强度M和比热C的测量中表明，Mn(PO₄)OH在T = 4.6 K时达到长程反铁磁有序。与磷锰矿Mn(PO₄)F和三斜磷锰矿型Co(PO₄)F不同，该标题化合物存在磁阻挫，其居里 - 外斯温度Θ与奈耳温度T的比值约为20。较大的阻挫强度值|Θ|/T源于锰多面体共角三角形的扭曲锯齿链几何结构，这种结构可能在三斜磷锰矿晶体结构的管状片段中孤立存在。
