Magnetization steps due to pairs of distant-neighbor spins in Zn"1"-"xCo"xSe and Zn"1"-"xCo"xS - Shapira, Y.; Yu, T.Q.; Lau, B.K.; Foner, S.; McNiff, E.J.; Heiman, D.; Thieme, C.L.H.; Niu, C.-M.; Wold, A.; Dwight, K.; Kershaw, R.; Bindilatti, V. (Elsevier)
Magnetization steps (MSTs) were observed in Zn"1"-"xCo"xSe and Zn"1"-"xCo"xS using temperatures T 〈 1 K, steady magnetic fields up to 200 kOe, and pulsed fields up to ~400 kOe. Unlike the MSTs observed earlier in other materials, these MSTs are due to pairs of distant-neighbor spins rather than to pairs of nearest-neighbor spins. For Zn"1"-"xCo"xSe the results give a second-neighbor exchange constant J"2/k"B = -3.04+/-0.1 K, and suggest a third-neighbor exchange constant J"3/k"B -0.8 K. An exchange constant J/k"B = -2.25+/-0.2 K observed in Zn"1"-"xCo"xS is either J"2 or J"3.
http://linkinghub.elsevier.com/retrieve/pii/0038-1098(90)90269-H
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