Cengellenmis, YaseminDertli, AbdullahAydin, Nuh2024-06-122024-06-1220181005-3867https://doi.org/10.1142/S1005386718000263https://hdl.handle.net/20.500.14551/20047this paper, we study lambda-constacyclic codes over the ring R = Z(4) + uZ(4), where u(2) = 0, for lambda = 1 + 3u and 3 + u. We introduce two new Gray maps from R to Z(4)(4) and show that the Gray images of lambda-constacyclic codes over R are quasi-cyclic over Z(4). Moreover, we present many examples of lambda-constacyclic codes over R whose Z(4)-images have better parameters than the currently best-known linear codes over Z(4).en10.1142/S1005386718000263info:eu-repo/semantics/closedAccessConstacyclic CodesCodes Over RingsQuaternary CodesGray MapsArticle253369376Q4WOS:0004417430000022-s2.0-85051465004Q3