Griffiths Phase and Mechanical Softening in La 0.7 Sr 0.3 MnO ₃ Modified With Nonmagnetic LaVO ₄ and SrMoO ₄ Secondary Phases

The Griffiths phase (GP) is discovered in La 0.7 Sr 0.3 MnO 3 ceramics modified with nonmagnetic LaVO 4 and SrMoO 4 secondary phases (formed from nominal V/Mo addition, sintered at 1300°C for 4 h, 0.05 ≤ x ≤ 0.2). The correlation between GP and mechanical degradation is reported for the first time. X‐ray diffraction confirms that V and Mo do not substitute for Mn but form secondary phases LaVO 4 and SrMoO 4 , which act as nonmagnetic additions. The downward curvature of the inverse magnetic susceptibility ( χ −1 ) above the Curie temperature ( T C ) signals a GP, indicating the presence of ferromagnetic clusters in the paramagnetic matrix. Below T C , the zero‐field‐cooled and field‐cooled magnetization curves bifurcate strongly, revealing glassy dynamics driven by these nonmagnetic defects. Increasing the defect concentration intensifies the GP singularity and simultaneously reduces hardness while raising the coefficient of friction. Specifically, Mo doping lowers the hardness from ∼457 HV to ∼100 HV and increases the friction coefficient by 40.5%. The mechanical softening originates from the combined effect of defect‐mediated grain refinement and magneto‐lattice coupling. This study offers new insights into the GP origin and opens avenues for designing mechanically robust manganites by controlling GP‐related defects.