We report the topochemical protonation of rutile oxides Rh_0.5V_0.5O₂ and Cr_0.5V_0.5O₂ by low-temperature hydrogen gas treatment. After the treatment, nonmagnetic V⁵⁺ (d⁰) ions were selectively reduced to +3.5 (d^1.5) for H_xRh_0.5V_0.5O₂ (x ∼ 0.75) and +4 (d¹) for H_xCr_0.5V_0.5O₂ (x ∼ 0.5). H_xRh_0.5V_0.5O₂ with nonmagnetic Rh³⁺ ions has weak magnetic interactions with a spin glass transition at T_f = 6 K. In contrast, protonation of Cr_0.5V_0.5O₂ with Cr³⁺ (d³) enhances antiferromagnetic interactions with the Weiss temperature of θ = −199(1) K. However, the spin glass transition temperature is still low (T_f = 10 K), indicating competing interactions, in which a frustration factor of 20 is the largest among rutile compounds. Topochemical protonation can be a useful method for extending the family of magnetic oxides.

中文翻译：

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质子化金红石氧化物中的自旋受阻

我们报告了通过低温氢气处理的金红石氧化物 Rh _0.5 V _0.5 O ₂和 Cr _0.5 V _0.5 O ₂的拓扑化学质子化。处理后，非磁性 V ⁵⁺ (d ⁰ ) 离子被选择性还原为 +3.5 (d ^1.5 ) H _x Rh _0.5 V _0.5 O ₂ ( x ∼ 0.75) 和 +4 (d ¹ ) H _x Cr _0.5 V _0.5 O ₂ ( x ∼ 0.5)。高_×铑_0.5 V _0.5 O ₂与非磁性 Rh ³⁺离子在T _f = 6 K 时具有与自旋玻璃化转变的弱磁性相互作用。相反，Cr _0.5 V _0.5 O ₂与 Cr ³⁺ (d ³ ) 的质子化增强了与韦斯温度θ = -199(1) K。然而，自旋玻璃化转变温度仍然很低（T _f= 10 K)，表示竞争性相互作用，其中金红石化合物中最大的挫败因子为 20。拓扑化学质子化是扩展磁性氧化物家族的有用方法。