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Two structurally similar homologous series of chiral liquid crystals derived from semifluorinated and non-fluorinated alkanes positioned at a chiral terminal chain have been synthesized and characterized by differential scanning calorimetry, polarizing optical microscopy and electric-optical measurements. It was found that there are two semifluorinated materials in the series I-m (m58, 10), that exhibit ferroelectric SmC* and antiferroelectric SmC Ã A phases. The corresponding non-fluorinated materials II-m (m58, 10), however, display only the SmC* phase, suggesting that the fluorinated materials encourage the formation of the antiferroelectric SmC Ã A phase. The spontaneous polarization (P s ) and apparent tilt angle (h) were measured, showing that the semi-fluorinated materials have higher P s and h values than non-fluorinated materials at any reduced temperature below the SmA*-SmC* transition.