Effect of pseudo-Tsai cluster incorporation on the magnetic structures of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>R</mml:mi><mml:mtext>−</mml:mtext><mml:mi>Au</mml:mi><mml:mtext>−</mml:mtext><mml:mi>Si</mml:mi></mml:mrow><mml:mo> </mml:mo><mml:mrow><mml:mo>(</mml:mo><mml:mi>R</mml:mi><mml:mo>=</mml:mo><mml:mi>Tb</mml:mi><mml:mo>,</mml:mo><mml:mi>Ho</mml:mi><mml:mo>)</mml:mo></mml:mrow></mml:math> quasicrystal approximants

In cluster-based quasicrystals, tetrahedra located in conventional Tsai clusters may be replaced by single rare-earth $(R)$ ions at the cluster centers (pseudo-Tsai clusters). this study, we investigate effect of pseudo-Tsai incorporation on magnetic structures two approximants, Tsai-type Tb-Au-Si [denoted TAS(0)] and Ho-Au-Si HAS(52)] with partial replacement clusters, up to 52%. The mixture can considered a different source randomness/disorder other than chemical mix sites (Au/Si). latter has been previously discussed regarding origin/cause spin-glass-like ordering Anderson localization electronic states quasicrystals approximant crystals. Single crystal neutron diffraction experiments 2 K were performed bulk physical properties (magnetization specific heat) investigated. addition, earlier collected powder data TAS(14) 14% was reanalyzed light results TAS(0) HAS(52). We find that arrangement ordered spins icosahedral shells these phases is similar, while cluster-center $R$ are different. case TAS(14), Tb moments seem affect surrounding moments, structure shell deviates from TAS(0). HAS(52), however, less affected $R$, averaged significantly diminished. discuss considering properties.