本研究旨在探討 Co1-xOsx 合金在絕對零度附近的量子相變行為，並深入研究化學無序效應對鐵磁性量子臨界點特性的影響機制。實驗採用電弧熔融法結合高溫退火處理製備出結構均勻且相純度高的多晶樣品，並透過X射線繞射與電子探針微區分析驗證樣品的晶體結構完整性與組成均勻性。利用物理性質量測系統在 1.8 K 至 300 K 溫度範圍內測量電阻率與比熱，並結合磁學性質量測系統獲取磁化強度及磁化率數據，全面掌握 Co1-xOsx 合金在不同 Os 摻雜濃度下的電、熱、磁響應。
實驗結果顯示，隨著 Os 摻雜濃度的增加，低溫殘餘電阻比呈現顯著下降趨勢，反映化學無序與自旋擾動效應的加劇，有效抑制傳統費米液體的行為。而透過修正 Arrott 圖分析及 WKF 標度分析，從 M(H) 曲線中擷取出臨界指數 ?、? 與 ?，其數值明顯偏離理論模型預測，與描述含無序擾動誘導一階相變的 BKV 理論高度吻合。此外，在臨界濃度 ? ≈ 0.44 附近，C/T 在 2 K 時達到最大值，暗示有效質量和費米能級態密度趨向發散，明確確立了量子臨界點的存在。
綜合分析非費米液體電性特徵、低溫比熱異常及非古典臨界指數行為，本研究不僅深入闡明了 Co1-xOsx 系統中化學無序與量子擾動的相互作用機制，更為凝態物理領域中量子相變提供了重要的實驗依據。

This study investigates the quantum phase transition behavior of Co1-xOsx alloys near absolute zero and explores the underlying mechanisms by which chemical disorder affects the characteristics of ferromagnetic quantum critical points. Polycrystalline samples with uniform structure and high phase purity were synthesized using arc melting followed by high-temperature annealing. The structural integrity and compositional homogeneity of the samples were verified through X-ray diffraction and electron probe microanalysis. Electrical resistivity and specific heat measurements were performed using a Physical Property Measurement System over the temperature range of 1.8 K to 300 K, while magnetization and magnetic susceptibility data were obtained using a Magnetic Property Measurement System, providing comprehensive characterization of the electrical, thermal, and magnetic responses of Co1-xOsx alloys across different Os doping concentrations.
The experimental results reveal that the low-temperature residual resistivity ratio exhibits a significant decrease with increasing Os concentration, reflecting the intensification of chemical disorder and spin fluctuation effects that effectively suppress conventional Fermi liquid behavior. Through modified Arrott plot analysis and WKF scaling analysis, critical exponents ?, ?, and ? were extracted from M(H) curves. These values deviate significantly from theoretical model predictions and show excellent agreement with the BKV theory, which describes disorder-induced first-order phase transitions. Furthermore, At the critical concentration ? ≈ 0.44, the C/T value reaches an maximum at 2 K, indicating that the electronic effective mass and density of states at the Fermi level approaches divergence and unambiguously establishing the existence of a quantum critical point.
Through comprehensive analysis of non-Fermi liquid electrical characteristics, low-temperature specific heat anomalies, and non-classical critical exponent behavior, this study not only elucidates the interplay between chemical disorder and quantum fluctuations in the Co1-xOsx system but also provides crucial experimental evidence for quantum phase transitions in condensed matter physics.

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