As a quasi-one-dimensional spin frustrated material, Ca
3Co
2O
6 has a series of interesting physical properties such as low-temperature spin freezing and multiple magnetized steps due to its unique structure. The magnetic properties of Ca
3Co
2O
6 mainly come from Co ions, and the doping of different elements at the Co site has a great effect on the magnetic structure of Ca
3Co
2O
6. At present, the magnetic research of Ca
3Co
2O
6 and its related compounds mainly focuses on exploring the influence of other elements replacing Co sites. For example, non-magnetic Sc
3+ can dilute the intrachain ferromagnetic exchange, while the doping of magnetic ions Mn
4+, Fe
3+ or Cr
3+ can inhibit the intrachain ferromagnetic interaction and enhance the antiferromagnetic interchain interaction. Doping Ti
4+ ions, which are high-valence non-magnetic ions, not only dilutes the magnetic interaction of Ca
3Co
2O
6, but also changes the valence state of cobalt ions. i.e. it can convert part of Co
3+ ions into Co
2+ ions. Therefore, comparing with other doped ions, their introduction may have a more significant effect on the magnetoelectric properties of Ca
3Co
2O
6. In this study, a series of Ca
3Co
2–xTi
xO
6 (
x = 0, 0.02, 0.04, 0.06) polycrystalline samples is prepared by sol-gel method. Their magnetic, dielectric and magnetodielectric properties are measured. The XRD patterns show that a small number of Ti
4+ ions do not change the crystal structure of Ca
3Co
2O
6. Due to the destruction of the long-range ferromagnetic correlation of Ca
3Co
2O
6 by non-magnetic Ti
4+ ions, the ferromagnetic interaction is inhibited to some extent. Because Ti
4+ ions are non-magnetic ions, they cannot form antiferromagnetic coupling with Co ions, resulting in the decrease of the Curie-Weiss temperature(
θ). The positive
θ value and exchange constant still indicate that the ferromagnetic interaction is dominant in Ti
4+ doped Ca
3Co
2–xTi
xO
6 (
x = 0, 0.02, 0.04, 0.06) samples. The substitution of non-magnetic ions Ti
4+ for Co
3+ ions also makes the effective magnetic moment of Ca
3Co
2–xTi
xO
6 (
x = 0, 0.02, 0.04, 0.06) monotonically decrease from
μeff = 5.42
μB for
x = 0 to
μeff = 5.18
μB for
x = 0.06. Accompanying the introduction of Ti
4+ ions, the spin frustration of Ca
3Co
2O
6 is released partly, thus gradually fading the magnetization steps of Ca
3Co
2O
6. As the Ca
3Co
2O
6 is a typical magnetodielectric material, the released spin frustration in Ti
4+ doped samples and the variation of the subtle magnetic structure exert a large influence on the magnetodielectric coupling effect of Ca
3Co
2–xTi
xO
6 (
x = 0, 0.02, 0.04, 0.06) compounds.