Unusual magnetic and transport properties in the Zintl phase Eu₁₁Zn₆As₁₂

Narrow-gap rare-earth Zintl phases frequently exhibit fascinating physical phenomena due to their various crystal structures, complex magnetic properties, and tunable transport behaviors. Here we report the synthesis, magnetic, thermodynamic, and transport properties of a Eu-containing Zintl arsenide, Eu₁₁Zn₆As₁₂, which exhibits complicated magnetic behavior. Two long-range magnetic transitions at 22 K (T_N) and 9 K (T^∗), as well as exceptionally strong ferromagnetic fluctuations around 29 K (T_F), are indicated by the susceptibility, heat capacity and resistivity measurements. Besides, Eu₁₁Zn₆As₁₂ displays metallic behavior, attributable to the hole carriers doped by slight Eu vacancies or the mixed valence of Eu²⁺ and Eu³⁺. A prominent resistivity peak occurs around T_N, which is rapidly suppressed by the applied field, leading to a prominent negative magnetoresistance effect. A resistivity hysteresis is observed below 5 K due to the remanent magnetization in the material, caused by the uncompensated ferromagnetic component. Our study presents the distinct magnetic and transport properties of Eu₁₁Zn₆As₁₂ and demonstrates that Eu-based Zintl phases are a fertile ground to study the interplay between magnetism and charge transport.