The dielectric properties and the phase transition behavior of (1-x)Pb($Yb_{1/2}Nb_{1/2}$)$O_3$ - $xPbZrO_3$ binary system have been investigated by X-ray diffraction, dielectric properties, E-P hysteresis loop and linear expansion coefficient measurements.
From the XRD measurements, the crystal structure has been found to change from orthorhombic like pure PYN to pseudocubic. As the composition of PZ increases, the transition temperature has been found to decrease gradually to x = 0.33. For x ≥ 0.33, relaxor behavior has been found. Also at x = 0.33, relaxor to normal phase transition has been found. For this relaxors, the hysteresis loops have changed from slim loop to linear type as the temperature is lowered. This may be interpreted by the V\'{o}gel-Fulcher relation and the freezing temperature ($T_f$) can be defined. In addition, the phase diagram is determined.
