biostudies-literatureXu DNational Natural Science Foundation of China35391-35399https://www.ebi.ac.uk/biostudies/studies/S-EPMC11538971biostudies-literatureUnknown14(48)Sodium and potassium have been doped into La₇SrCu₄O_16-<i>δ</i> to form La_7+2<i>x</i> Sr_1-4<i>x</i> K _<i>x</i> Na _<i>x</i> Cu₄O_16-<i>δ</i> solid solutions by a solid-state reaction, which crystallizes in the <i>I</i>4/<i>mmm</i> space group when 0 ≤ <i>x</i> < 0.16 and <i>Fmmm</i> when 0.16 < <i>x</i> ≤ 0.25. With the equivalent replacement of four Sr²⁺ by one Na⁺, one K⁺ and two La³⁺, it is very interesting to find that <i>T</i> ^zero _c (the definition is presented in the introduction part) of La_7+2<i>x</i> Sr_1-4<i>x</i> K _<i>x</i> Na _<i>x</i> Cu₄O_16-<i>δ</i> doesRSC advancesSynthesis, structure, and superconductivity of La&lt;sub&gt;7+2&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; Sr&lt;sub&gt;1-4&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; K &lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; Na &lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; Cu&lt;sub&gt;4&lt;/sub&gt;O&lt;sub&gt;16-&lt;i&gt;δ&lt;/i&gt;&lt;/sub&gt;.PMC1153897122175003Li GJu JYin CXu DGeng JWang XWang YCai GHuang PWu XfalseSynthesis, structure, and superconductivity of La&lt;sub&gt;7+2&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; Sr&lt;sub&gt;1-4&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; K &lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; Na &lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; Cu&lt;sub&gt;4&lt;/sub&gt;O&lt;sub&gt;16-&lt;i&gt;δ&lt;/i&gt;&lt;/sub&gt;.Sodium and potassium have been doped into La₇SrCu₄O_16-<i>δ</i> to form La_7+2<i>x</i> Sr_1-4<i>x</i> K _<i>x</i> Na _<i>x</i> Cu₄O_16-<i>δ</i> solid solutions by a solid-state reaction, which crystallizes in the <i>I</i>4/<i>mmm</i> space group when 0 ≤ <i>x</i> < 0.16 and <i>Fmmm</i> when 0.16 < <i>x</i> ≤ 0.25. With the equivalent replacement of four Sr²⁺ by one Na⁺, one K⁺ and two La³⁺, it is very interesting to find that <i>T</i> ^zero _c (the definition is presented in the introduction part) of La_7+2<i>x</i> Sr_1-4<i>x</i> K _<i>x</i> Na _<i>x</i> Cu₄O_16-<i>δ</i> does2024-01-01T00:00:00Z2024 Nov2025-04-06T23:50:52.003Z2025-04-04T14:40:12.25ZS-EPMC115389713950768810.1039/d4ra06045h